What is Exponent: Definition and 220 Discussions

Exponentiation is a mathematical operation, written as bn, involving two numbers, the base b and the exponent or power n, and pronounced as "b raised to the power of n". When n is a positive integer, exponentiation corresponds to repeated multiplication of the base: that is, bn is the product of multiplying n bases:





b

n


=




b
×

×
b





n



times




.


{\displaystyle b^{n}=\underbrace {b\times \dots \times b} _{n\,{\textrm {times}}}.}
The exponent is usually shown as a superscript to the right of the base. In that case, bn is called "b raised to the nth power", "b raised to the power of n", "the nth power of b", "b to the nth power", or most briefly as "b to the nth".
One has b1 = b, and, for any positive integers m and n, one has bn ⋅ bm = bn+m. To extend this property to non-positive integer exponents, b0 is defined to be 1, and b−n (with n a positive integer and b not zero) is defined as 1/bn. In particular, b−1 is equal to 1/b, the reciprocal of b.
The definition of exponentiation can be extended to allow any real or complex exponent. Exponentiation by integer exponents can also be defined for a wide variety of algebraic structures, including matrices.
Exponentiation is used extensively in many fields, including economics, biology, chemistry, physics, and computer science, with applications such as compound interest, population growth, chemical reaction kinetics, wave behavior, and public-key cryptography.

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  1. M

    Laws of Exponents: Solve Math Homework Questions

    Hello, this isn't really a physics question but I'm getting pretty desperate and you guys have always been able to help me out before :) 1. Homework Statement http://imgur.com/mYtJDLI Homework Equations I believe I'm suppose to use the Laws of Exponents. For the first set possibly but not...
  2. C

    Solving for x in exponent

    Homework Statement Solve the equation 4^{x-1} = 2^x + 8. Homework Equations Just algebra The Attempt at a Solution 4^{x-1} = 2^x + 8 2^{2(x-1)} = 2^x + 2^3 2^{2x}2^{-2} = 2^x + 2^3 \frac{2^{2x}}{2^2} = 2^x + 2^3 2^{2x} = 2^22^x + 2^5 2^x2^x - 2^22^x = 2^5 2^x(2^x - 2^2) = 2^5 I...
  3. G

    Rational exponents (was: Math Discussion)

    Homework Statement (-64)^(3/2) Homework Equations None. The Attempt at a Solution There is no answer that can be reached and it is supposed not be a real number. I was wondering why that is. How is it that there is no "real" answer to this problem?
  4. P

    Comparing Exponentiation: 20^100 vs. 400^40?

    Homework Statement Without using a calculator and without evaluating expressions, determine which is greater. 20^100 or 400^40 Homework Equations None, however some exponent laws and possibly mental math are applicable. The Attempt at a Solution I don't know how to reach an answer without...
  5. P

    Exponent Laws Related Homework Question

    Homework Statement For which non-zero value of x is the equation -x^ -4 = (-x)^ -4 true? Explain. Homework Equations None. Other than applicable exponent laws. The Attempt at a Solution I know how to use the guess and check method. But I was wondering how to reach the answer faster and how...
  6. S

    MHB How this exponent expression is reduced

    Initially the expression A has 8 terms. So how is it reduced in the second line to 5 terms? Could you show me, please? Thank you. \begin{align*} A&=10^{28} -10^{22} +61\times10^{14}+12\times10^{21}-12\times10^{15}+3\times10^{9}-36\times10^{8}+9\times10^{2}\\ &=10^{28}...
  7. H

    MHB What algebra rule is used here to give the exponent 2 in step 2?

    First it starts as r= p* (50K^-.5 100^.5) then K=[(50p100^.5/r]^2 So how does the power of 2 get there in the second part when moving K to the other side?
  8. L

    Lyapunov exponent -- Numerical calculations

    In computational physics is very often to calculate largest Lyapunov exponent. If largest Lyapunov exponent ##LE## is positive there is chaos in the system, if it is negative or zero there is no chaos in the system. But what can we say about some certain value of ##LE##. For example...
  9. M

    Root and exponent of matrix

    Homework Statement I. 3*3 matrix A (8 2 -2, 2 5 4, -2 4 5) II. 3*3 matrix (1 2 0, -1 -2 0, 3 5 1) Homework Equations I. Solve Aexp 100 of 3*3 II. Find the 5th rooth of B matrix The Attempt at a Solution I. I got stuck at diagonalising the matrix. Is this OK 1st step ? If yes...
  10. mhsd91

    The Matrix Exponent of the Identity Matrix, I

    So, essentially, all I wonder is: What is the The Matrix Exponent of the Identity Matrix, I? Silly question perhaps, but here follows my problem. Per definition, the Matrix Exponent of the matrix A is, e^{A} = I + A + \frac{A^2}{2} + \ldots = I + \sum_{k=1}^{\infty} \frac{A^k}{k!} =...
  11. Prof. 27

    Logarithm Issue. Unable to find answer sheet answer

    Homework Statement log39x4 - log3(3x)2 The answer sheet says that the answer is 0, but when I work the problem both ways I get: 2log3x Any ideas? Homework Equations logxy/z = logxy - logxz The Attempt at a Solution Formula Sheet 20-30 Minutes of Messing around with the problem
  12. B

    How TI-89 Calculator Rearranged Exponent Confusion - Ben

    My TI-89 calculator rearranged $$ 2^{2m+1}-1$$ to $$ 2\times 4^m - 1 $$ I can't for life of me work out how it did it. Is anybody able to put me out of my misery? Thank you in advance! Ben
  13. T

    MHB How to calculate binomial (n choose k) coefficients when exponent is negative?

    I'm using Pascal's (n choose k) method for calculating the coefficients of the terms of a binomial expansion. However, if the exponent is a negative integer, how can one use this method, seeing as factorials for negative integers are undefined. For example, how could one determine the...
  14. S

    A question regarding the definition of e

    Homework Statement In writing the definition of ##e## i.e. ##e=\displaystyle\lim_{n\rightarrow\infty}(1+\frac{1}{n})^n##, why do we denote the variable by 'n' despite the fact that the formula holds for n∈(-∞,∞)? Is there any specific reason behind this notation i.e. does the variable have...
  15. O

    MHB Why does raising a number to the power of 0 always result in 1?

    Why is base to power 0 always 1, even if it's .2^0 it =1? Is it just counting the 1 time the .2 is existing? Is that why?And - base ^ 0 is negative whatever the number is so why is that not a negative one? Because (-2)^2 is 4 but no because a negative times a negative is a positive. And...
  16. kelvin490

    Strain hardening exponent Question

    For some metals and alloys the region of the true stress–strain curve from the onset of plastic deformation to the point at which necking begins may be approximated by σ=Kεn where n is strain hardening exponent. I wonder whether this equation can be applied to engineering stress-strain curve or...
  17. B

    Modern Algebra: Proof of an exponent law

    The problem is to verify ##(g^n)^{-1} = g^{-n}## is true ##\forall n \in \mathbb{Z}##. Here is my proof: ## (g^n)^{-1} = (\underbrace{g \star g~ \star ~...~ \star g}_{n~ \mbox{copies}})^{-1} \iff## ##(g^n)^{-1} = [(g \star ~...~ \star g) \star g]^{-1}## Using ##(a \star b)^{-1} = b^{-1}...
  18. O

    MHB How do you solve for an exponent that is pi and a cube root?

    How do you solve when an exponent is pi? And a cube root. Thanks, sorry I'm slow.
  19. M

    What is the meaning and properties of negative exponents?

    hello! I want to know what happens, what means, what the properties are etc of a negative exponent I read on wikipedia "When n is a negative integer and b is non-zero, b^n is naturally defined as 1/b^−n" So based on the above, 3^-2 = 1/3^2 1) Is this correct? 2) Why does this...
  20. T

    Integrating exponent to get delta function

    Something i ran into while doing hw Homework Statement starting with \int{dx} e^{-ikx}\delta(x) = 1 we conclude by Fourier theory that \int{dk} e^{+ikx} = \delta(x) Now, i try to compute \int{dk} e^{-ikx} (I've dropped the normalization factors of 2\pi. I believe no harm is done by...
  21. bcrowell

    Exponentiation with zero base, complex exponent?

    Is there a good general definition of 0^z, where z may be complex? The cases where z is real (and positive, negative, or zero) are straightforward, but what if z isn't real? Are there arbitrary branch cuts involved, or is there some universal definition?
  22. ecoo

    Exponent on Negative Number

    How come when you do something like -3^2=-9. Does it mean that the dash is a subtraction symbol and not a negative symbol?
  23. Saitama

    MHB Cube root of unity with a huge exponent

    Problem: Let $y=x/(1+x)$, where $$\Large x=\omega^{2009^{2009^{\cdots \text{upto 2009 times}}}}$$ and $\omega$ is a complex root of 1. Then $y$ is A)$\omega$ B)$-\omega$ C)$\omega^2$ D)$-\omega^2$ Attempt: I somehow need to show that the huge exponent is of the form $3k$, $3k+1$ or $3k-1$...
  24. K

    MHB Interval of stability, Lyapunov exponent

    For the function fc(x)= (6/x) + (x/2) -c, generate an estimate of the Lyapunov exponent for at least one c value chosen from each of the following intervals : (note 0 <= c <= 3) a) the interval of stability of the fixed point b) the interval of stability of the 2-cycle c) the interval of...
  25. T

    Solving exponential equations with x as the exponent

    My confusion comes from basic exponent rules and whether or not both sides of an equation have to have the same level of exponent, when you reduce the base for solving. If one side can have an exponent of 3, does the other side also have to be reduced to something that would also have an...
  26. N

    Matrix Inversion and the Associative Property

    Homework Statement Is it true that: (ABA^-1)^8 = AB^8A^-1 for all n x n matrix and not just for invertible matrix? My attempt: (ABA^-1)^8 =A^8B^8A^-8
  27. P

    Hyperbolic Sine - Exponent transition

    Hey I didn't understand the transition below, I'd be glad for some help thanks
  28. mente oscura

    MHB Express numbers, raised to an exponent, for sum of consecutive numbers.

    Hello. Not long ago, I did a study on numbers, raised to an exponent. I noticed that a "pattern" remained, and I could find a general formula. Let: a , n, k \in{N}, when "a" is odd number: I define: a _1, \ldots , a_k \in{N}, as the consecutive addends, such that: Let: a , n, k \in{N}...
  29. L

    Closed form for geometricish series (index squared in the exponent)?

    Closed form for "geometricish" series (index squared in the exponent)? Hi all, Is there a nice closed form for the following series? \sum_{k=0}^n x^{k^2} Even a decently tight upper bound and lower bound would be nice (obviously it is bounded by the corresponding geometric series \sum...
  30. anemone

    MHB Solving an Exponent Equation: How to Prove the Two Solutions?

    Hi MHB, Problem: Solve in the set of real numbers the equation $5^x+5^{x^2}=4^x+6^{x^2}$. Attempt: At first glance, we can tell $x=0, 1$ would be the two answers to the problem but how do we prove these two are the only answers? I think this problem must have something to do with the Mean...
  31. S

    MHB Manipulating Exponents to Simplify Fractional Expressions

    I'm trying to manipulate (x+1)^x+1 / ((x+1)+1)^x+1 So that I have a 1 in the numerator. If I bring the numerator down using the integer exponent rule, I'll have... 1 / ( (x+1) / (x+1) + 1 )^x+1 ? Whoops, that's not right... 1 / (x+1)^x * ((x+1)+1)^x+1 ?
  32. M

    Inequalities, trigonometric and x exponent.

    These are the two last problems I'll bother you with for a short while (I love this forum, I'll definitely stay on and hopefully be able to contribute in the future). Homework Statement Problem 1: (##-x^2##-1)sin2x > 0 , xe[0,2\pi] Problem 2: ##2^{-x^2+x+2}## < 4 Homework...
  33. anemone

    MHB Solve Exponent Challenge: Prove Equality

    Prove that \left( 6+845^{\frac{1}{3}}+325^{\frac{1}{3}} \right)^{\frac{1}{3}}+\left( 6+847^{\frac{1}{3}}+539^{\frac{1}{3}} \right)^{\frac{1}{3}}=\left( 4+245^{\frac{1}{3}}+175^{\frac{1}{3}} \right)^{\frac{1}{3}}+\left( 8+1859^{\frac{1}{3}}+1573^{\frac{1}{3}} \right)^{\frac{1}{3}}
  34. S

    What is the Polytropic Exponent, n Value for a Singular Repeating Compressor?

    Homework Statement So, after performing an experiment a number of times, to calculate the efficiency of a singular repeating compressor, I have found n ≈ 1 i.e. it equals 1.01... in all of my found values. I've now been asked to classify the type of process. Seeing as technically n > 0 and n<...
  35. C

    MHB Find derivative of function with fractional exponent?

    I need to find the derivative of R(t)=5t-3/5 are there any derivative rules I can use for this problem?
  36. F

    MHB Separation of variables, can't get y out of exponent

    Solve the DE by using separation of variables \frac{dy}{dx} = e^{3x+2y} Break up e^{3x+2y} = e^{3x}e^{2y} Move x's and y's to their own side of the equation. \frac{1}{e^{2y}} dy = e^{3x} dx Integrate both sides of the equation to get \frac{-e^{2y}}{2x}=\frac{e^{3x}}{3}+C I don't know how to...
  37. T

    Scientific notation, and an exponent question

    I'm curious but usually negative exponents mean you're going to put those numbers on the bottom (sorry forgot the exact term it is much earlier than I normally get up) (example 6^-1 =1/6 so why is scientific notation different? Or is it? (Ex: 5x10^-3=.005)
  38. W

    How to re-arrange formula with an exponent

    I have been out of school for 35 years and this is out of my reach. Can someone please re-arrange this formula solved for Tp . T = (Tp / Sa) to the .833 power I have an example in it's current form. T = 40.5 Deg C Tp = 2300mW/CM cubbed Sa = 27 CM squared
  39. J

    Derivative of Sine Function Raised to An Exponent

    Homework Statement Find the derivative of (sin x) ^ ((sin(sin x)))Homework Equations The Attempt at a Solution I get sin(sin x) * [(sin x) ^ {(sin(sinx)-1)}* cos x] The cos x isn't part of the exponent Is this right? Thanks :)
  40. M

    Proving Basic Exponent Properties for a Group

    When proving that x^m x^n = x^{m+n} and that (x^m)^n = x^{mn} for all elements x in a group, it's easy enough to show that they hold for all m \in \mathbb{Z} and for all n \in \mathbb{N} using induction on n. The case n = 0 is also very easy. But how does one prove this for n \in...
  41. M

    Lyapunov Exponent: Calculate for Linear Map xn+1= rxn

    Homework Statement Calculate the Lyapunov exponent for the linear map xn+1= rxn. Homework Equations λ = Lyapunov Exponent λ = \lim_{n \rightarrow \infty} \begin{bmatrix}\dfrac{1}{n} \sum_{i = 0}^{n - 1} ln|f'(x_i)| \end{bmatrix} The Attempt at a Solution f'(x) = r. λ =...
  42. E

    Log Function and Exponent Precedence

    Homework Statement This isn't really a specific problem, just a question if hand-writing log functions (or trig functions) is interpreted differently than when typing them into a calculator or something like Wolfram Alpha. Suppose you have this on paper: ln ex Is this the same as...
  43. A

    MHB Simplification of an equation based on exponent rules

    I have the following equation that I'm trying to simplify: $$\frac{5 + \sqrt{5}}{2\sqrt{5}}*(\frac{1 + \sqrt{5}}{2})^{x} $$ From looking at it, it seems like it could be simplified so that the right-hand side of the multiplication would be: $$(\frac{1 + \sqrt{5}}{2})^{x+1} $$ I started to...
  44. A

    Solving Exponent Problem: Find Value of x

    Homework Statement x^X^x^x^x=2. find value of x. Homework Equations taking log both sides, but it makes a equation which i am not able to solve. The Attempt at a Solution x^(x)^4=2 x^4logx=log2. what next?
  45. A

    MHB Find the finite sum of the square and cube exponent of integers

    Hey, it is clear for me that \sum_{i=1}^{n} i = \frac{n(n+1)}{2} how to find a formula for \sum_{i=1}^{n} i^2 \sum_{i=1}^{n} i^3 Thanks
  46. Square1

    Whole exponent vs. fraction exponent

    a^x means a*a*a*a... x times This makes sense for whole numbers to me, but I am sort of lost about transfering the definition one x becomes a fraction. I know that the denominator in a fraction in an exponent means "the denominator root"..., and I know what a root its. But it is a jump in...
  47. T

    Isolating a variable in an exponent

    Homework Statement So I had to find out N=Noe-ux Where No=1.5,e is the elementary charge, u=-0.068 and x=0.07 I came to the answer 1.221 Now I need to find x if u =-0.036, N=1.221 and No remains 1.5Homework Equations The Attempt at a Solution I reduce the equation to the following...
  48. T

    Question about should I do exponent rule before quotient rule for derivative

    Homework Statement ([2x+1/4x+3]^2) Homework Equations Exponent and quotient rule The Attempt at a Solution Would this become: 2* (2x+1/4x+3) then do the quotient rule?
  49. P

    MHB Exponent of convergence of a sequence of complex numbers

    Def. Let $\{z_j\}$ be a sequence of non-zero complex numbers. We call the exponent of convergence of the sequence the positive number $b$, if it exists, $$b=inf\{\rho >0 :\sum_{j=1}^{+\infty}\frac{1}{|z_j|^{\rho}}<\infty \}$$ Now consider the function $$f(z)=e^{e^z}-1$$ Find the zeros $\{z_j\}$...
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