Expression Definition and 999 Threads

  1. M

    I hope this helps!Translating Statements into Logical Formulas

    Is the statement "if you are a comedian then you are funny." equivalent to what is defined in part (a)?
  2. S

    MHB Solving Complex Expressions for Scientists

    How to go about solving this one? (1-i)-1+i so far i have tries using the famous Uv=ev(ln(U) im stuck where i get e-1/2ln(2)+(pi/4)-2kpi*ei(-1/2ln(2)+(pi/4)-2kpi)
  3. S

    MHB What Are the Possible Values of 2^(-i)?

    Find all possible Values of: 2(-i)
  4. M

    How do I simplify (sin t + cos t)2 / sin t cos t?

    Homework Statement Simplify: (sin t + cos t)2 / sin t cos t Homework Equations tan t = sin t/cos t cot t = cos t/sin t cot t = 1/tan t The Attempt at a Solution (sin t + cos t)2 / sin t cos tsin2 t + 2sin t cos t + cos2 t / sin t cos t(sin t/cos t) + 2 + (cos t/sin t) tan t + cot t + 2...
  5. M

    Simplifying a trigonometry expression

    Homework Statement Simplify: [(sec x)(sec2 x) - (tan x - 1)(sec x tan x)] / sec2 x Homework Equations none The Attempt at a Solution [(sec x)(sec2 x) - (tan x - 1)(sec x tan x)] / sec2 x [(sec x)(sec2 x) - tan x (1 -1) sec x ] / sec2 x [(sec x)(sec2 x) - 0 ] /...
  6. C

    Eliminate the denominator in this expression

    Homework Statement Eliminate the denominator on the RHS of the following expression sin(\alpha)-sin(\beta) = -\frac{-v(sin(\alpha) cos(\alpha) + sin(\alpha) cos(\beta)}{c-vcos(\alpha)} and from it, derive sin(\alpha)-sin(\beta) = -\frac{v}{c}(sin(\alpha)cos(\beta)+sin(\beta)cos(\alpha))...
  7. A

    Why is this expression bounded by 1?

    How exactly might one go about showing that \left| \frac{1 - e^{-iy}}{-iy} \right| is bounded by 1 for y\in \mathbb R? I thought this would be easy to show using the series expansion of e^{-iy} in some way: \left| \frac{1 - e^{-iy}}{-iy} \right| = \left| 1 - \frac{iy}{2} -...
  8. S

    Inverse Laplace Transform of this expression?

    Homework Statement Find the Inverse Laplace Transform of \frac{1}{(s^{2} + 1)^{2}} Homework Equations The Attempt at a Solution I tried using partial fractions but it didn't work. It looks like a cosine transform, but I don't know what else to do. Help please :(
  9. C

    Find an Expression for the Helmholtz free energy

    Homework Statement I am attempting the problem below, I might have the correct answer but would appreciate if someone could confirm this (or tell me where I'm going wrong). Consider a statement having 2 states, one at energy 0 and one at energy ε. Find an expression for the Helmholtz free...
  10. anemone

    MHB Find the Units Digit of An Expression

    What is the units digit of $$\left\lfloor \frac{10^{20000}}{10^{100}+3} \right\rfloor$$?
  11. alyafey22

    MHB Creating a Summation Expression with k and m Variables

    How to write something similar to the following Or is it better to write $$\sum_{n=k ,m=1}^{k+1}$$
  12. D

    MATLAB A simple symbolic expression in Matlab

    I tried to check x²-1 = (x+1)(x--1) So I did the following: Matlab returns 0. Any suggestions? :) (Matlab beginner by the way)
  13. K

    Simple algebra/trig expression, simplifying

    Hello, I'm trying to solve this equation. (4-4cos(∏*0.16*4)) - (4-4cos(∏*0.16*3)) It seems like it should be so easy. First I start with the left hand side (∏*0.16*4). Then I take the cosine of that, and then multiply it by 4. Then I do 4 - [answer] to get a value for the full left side...
  14. S

    MHB How can I confidently find the value of z in the given equation?

    Find the value of $$z = \frac 1{\cos x} + \tan x$$ given $$\frac 1{\cos x} - \tan x = 2$$. By squaring and using trigonometric identities on the given equation, one can arrive at $$\frac {1- \sin x}{1 + \sin x} = 4$$ The unknown expression $$z$$ can, by squaring, be written as $$z^2 = \frac...
  15. anemone

    MHB Evaluate Trigonometric Expression Challenge

    Evaluate $$\tan\frac{\pi}{13}\tan\frac{2\pi}{13}\tan\frac{3 \pi}{13}\tan\frac{4\pi}{13}\tan\frac{5\pi}{13} \tan \frac{6\pi}{13}$$.
  16. N

    How to simplify following trignometric expression

    Homework Statement - 1/[cosx(cos(x-90))] The Attempt at a Solution = - 1/[cosx(-cos(90-x))] //so first I take the negative sign out from (x-90) to make it (90-x) = +1/[cosx(cos(90-x))] // negative sign from outside the cos and outside the entire fraction combine to...
  17. V

    Calculating an expression for trace of generators of two Lie algebra

    Suppose we have $$[Q^a,Q^b]=if^c_{ab}Q^c$$ where Q's are generators of a Lie algebra associated a SU(N) group. So Q's are traceless. Also we have $$[P^a,P^b]=0$$ where P's are generators of a Lie algebra associated to an Abelian group. We have the following relation between these generators...
  18. Saitama

    Simplifying a trigonometric expression

    Homework Statement If ##\displaystyle \tan\left(\frac{\pi}{4}+\frac{y}{2}\right)=\tan^3\left( \frac{\pi}{4}+\frac {x}{2} \right)##, prove that $$\frac{\sin y}{\sin x}=\frac{3+\sin^2 x}{1+3\sin^2x}$$Homework Equations The Attempt at a Solution...
  19. QuantumCurt

    Find the exact value of the trigonometric expression

    Homework Statement Find the exact value, without using a calculator. \ cos(\frac{\pi}{15}) \ cos(\frac{\pi}{45}) The Attempt at a Solution I started off using a product to sum formula- \frac{1}{2}[cos(\frac{4\pi}{45})+ \ cos(\frac{2\pi}{45})] Now I don't know where to...
  20. E

    Equivalent form for Binomial Expression?

    Is there a way to express ##{n\choose k}{n\choose r}## in another form without n as the "top" of the binomial coefficient? I remember seeing it once but I forgot what it was.
  21. paulmdrdo1

    MHB How would you simplify this logarithmic expression?

    how would you simplify this $\displaystyle \frac{1}{5}\ln|\sin5x|+\frac{1}{5}\ln|\csc5x-\cot5x|$ please explain.
  22. anemone

    MHB Evaluating Trigonometric Expression

    Without the use of a calculator, evaluate $$\tan^2 20^{\circ}+\tan^2 40^{\circ}+\tan^2 80^{\circ}$$.
  23. Saitama

    What is the Range of the Given Expression When ##\sin 2\beta≠0##?

    Homework Statement If ##\beta## is such that ##\sin 2\beta≠0##, then show that the expression ##\displaystyle \frac{x^2+2x\cos\alpha+1}{x^2+2x\cos\beta+1}## (x real) always lies between ##\cos^2\alpha/\cos^2\beta## and ##\sin^2\alpha/\sin^2\beta##. Homework Equations The Attempt at...
  24. L

    Find the Expression of an Electric Field Produced by a Dipole

    Homework Statement An electric dipole is located along the y-axis as shown in (picture attached). The magnitude of its electric dipole moment is defined as p=2aq. (a) At a point P, which is far from the dipole (r>>a), show that the electric potential is V=\frac{k_{e}pcosθ}{r^{2}} (b)...
  25. Q

    Calculating an expression for work in a magnetic field

    As shown, I must derive a formula to find work. http://i.imgur.com/0U0eLqm.jpg I proceeded as follows. W= F * D = (B * I * L) * D V = BA/T I = V/R = (BA/t)/R = BA/tR F = B * (BA/tR) * A W = ((B^2*A^2)/tR) * A W = (B^2 * A^3)/tR Does that seem right? IIRC, the B*I*L formula is only...
  26. V

    Calculating the residue of complicated expression

    Homework Statement Hi, I want to calculate the residue of this expression: Homework Equations I know that the residue of a function with a pole of k-th order is given by this: The Attempt at a Solution I know that the function has infinite number of poles at k*∏, for k=-∞ to...
  27. N

    Mathematica Mathematica: Recursive expression

    Hi I am trying to find a smart way to write the following fraction, $$ F = \frac{a_1}{1+\frac{a_2}{1+\frac{a_3}{1+a_4}}} $$ Here we can just take a_n= n for simplicity. My fraction is in principle infinite, but I am trying to construct a function which can find F for a given n recursively. I...
  28. U

    Find the maximum value of this expression

    Homework Statement \dfrac{tan\left( \theta + 2\pi /3 \right) - tan\left( \theta + \pi /6 \right) + cos\left( \theta + \pi /6 \right)}{\sqrt{3}} \\ \theta \in \left( -5 \pi /12, - \pi /3 \right) The Attempt at a Solution At maximum, f'(x)=0 sin(θ+∏/6)=0 But there is no theta in...
  29. Sudharaka

    MHB Simplifying an Expression (Heather Jean's Question from Facebook)

    Heather Jean's of Facebook writes: Simplify, \[-(6y-\gamma)-5(-\gamma+6y)\]
  30. N

    Canonical expression and truth table

    Hey, What are the steps to follow to draw a truth table and create canonical expression from a given expression A? Lets say I have A= B'.(C'+D) 1) first I have to draw the truth table for the expression above, but How could I do that since I only have one expression? 2)Then I...
  31. Femme_physics

    Rewriting an expression what math operation did my teacher do?

    Rewriting an expression...what math operation did my teacher do? I'm trying to see how did my teacher rewrite this expression in the following manner: What mathametical operation did he do? I really can't see it...
  32. Femme_physics

    How can I simplify this expression without getting confused?

    My basic math is failing me again :( My attempt to simply: My teacher's attempt: Ignore the difference in notation. He writes || which signifies (A x B) / (A + B) = A || B And yes I'm aware there is more to simplify but I fail to follow him on the first step
  33. J

    Writing Common Ion Concentration in Buffer Eq. Expression

    Homework Statement What is the pH of a buffer solution created by combining 100 mL of 0.2 M acetic acid and 400 mL of 0.10 M sodium acetate? Ka= 1.8 x 10^(-5)Homework Equations 1.8 x 10-5=([C2H3O2-][H+])/([HC2H3O2]) The Attempt at a Solution I know what I'm supposed to do to solve this...
  34. P

    Simplify Expression and Find Product of a*b + 15m + 11n + 8

    for which value of a the expression write a*m*b+15*m+11*n+8 can be written into a product of something(with m)*something (with n) i can think how to find the product of this expression
  35. I

    How to evaluate this nabla expression in spherical coordinates?

    I'm currently working out the Schrödinger equation for a proton in a constant magnetic field for a research project, and while computing the Hamiltonian I came across this expression: (\vec{A}\cdot\nabla)\Psi where \Psi is a scalar function of r, theta, and phi. How do you evaluate this...
  36. G

    Reduction of Boolean Expression to its Lowest From

    Hey Guys I am Currently doing my degree in information systems. At the moment the subject is PLC(Processing and Logic Concepts) I understand all of it, I am not sertain on how to start reducing a boolean expression. Once the first step is done I normally get it and can complete the...
  37. B

    MHB Evaluating Arithmetic Expression

    I need help figuring out what the little 2 next to an equation means this is what my problem looks like I have the answer but I can't figure out how it was found out. (3)(-4)2 - (3)(-5) so the 2 next to the 4 in parentheses is little.
  38. E

    How to correctly code the expression with Ei function?

    Hi, I am trying to incorporate the following equation into Matlab in the red: http://http://www.radikal.ru][PLAIN]http://s018.radikal.ru/i518/1305/16/1cc0d2a72d38.jpg The following data is to be used: t=3000000 nr=nx=161 q=0.02 k=5e-13 mu=0.00035 c=1.5e-8 phi=0.25 rw=0.1 h=4.5...
  39. ECHOSIDE

    I'm having trouble factoring this rational expression.

    Homework Statement ((a^3-b^3)/(a^2-2ab+b^2))/((2a^2+2ab+2b^2)/(9a^2-9b^2)) Not using complex number system. Not concerned with domain. Find the quotient and put it in simplest terms. Homework Equations The Attempt at a Solution Too many to transcribe. Apparently I'm missing...
  40. P

    Energy a mathematical expression?

    So, energy is simply a mathematical expression of how much work is done in the system? Since energy is not a "physical" object that has mass. It's not matter at all. If so, the laws of conservation makes sense, it can't be created nor destroyed. But I can't imagine how a mathematical...
  41. anemone

    MHB Evaluate Trigonometric Expression.

    Evaluate $$\cos \left(\frac{\pi}{65}\right)\cdot\cos \left(\frac{2\pi}{65}\right)\cdot\cos \left(\frac{4\pi}{65}\right)\cdot\cos \left(\frac{8\pi}{65}\right)\cdot\cos \left(\frac{16\pi}{65}\right)\cdot\cos \left(\frac{32\pi}{65}\right)$$.
  42. X

    Algorithm or expression to put n elements in k sets

    I have 17 elements, and I want to put them in 3 sets. This makes 2 sets with 6 elements, and 1 set with 5 elements. Now I want to find an algorithm to partition n elements in k sets. Can anyone give me an algorithm, or a math expression for me to implement in a algorithm? Thanks
  43. anemone

    MHB Factoring Algebraic Expression

    Factor the expression $$30(a^2+b^2+c^2+d^2)+68ab-75ac-156ad-61bc-100bd+87cd$$
  44. N

    Electrical: Reduce the expression to the form V_mcos(wt+theta)

    Homework Statement Reduce the Expression: 15sin(wt-45°) + 5cos(wt-30°) + 10cos(wt-120°) to the form Vmcos(wt+θ) Homework Equations The Attempt at a Solution My theta value at the end isn't coming out right. My first step was to put make sure each term was in terms...
  45. B

    Truth table to boolean expression

    I have a 9 input to 9 output truth table I constructed using Python. I am trying to find a program that can deduce the (hopefully minimized) Boolean expression for my outputs. I tried Logisim already, but when I try to paste the enormous data (512 rows), my Logisim crashes. Can anyone recommend...
  46. anemone

    MHB Factoring Trigonometric Expression.

    Decompose the expression below into real factors: $$1-\sin^5 x-\cos^5 x$$
  47. B

    MHB An approximated lower bound of an expression.

    Hii All, $ \sum_{i=1}^{x}i^{N}:N>2 $. Is there any approximated lower bound for the above summation? Is it > $ \frac{1}{N+1}x^{(N+1)}$ ? If yes, how to prove that?regards, Bincy
  48. K

    Closed form expression of the roots of Laguerre polynomials

    The Laguerre polynomials, L_n^{(\alpha)} = \frac{x^{-\alpha}e^x}{n!}\frac{d^n}{dx^n}\left(e^{-x}x^{n+\alpha} \right) have n real, strictly positive roots in the interval \left( 0, n+\alpha+(n-1)\sqrt{n+\alpha} \right] I am interested in a closed form expression of these roots...
  49. E

    I in simplifying this boolean expression

    Can someone please show me how to simplify this expression? I have no clue of how it's done so any help would be appreciated. Thank you! x'y'+xz'+yz+x'yz'+xy'z
  50. 1

    Calculate the value of this real+imaginary expression:

    Homework Statement Let z = 2 + i and u = -3-3i. Calculate the value of |z/u|. Homework Equations None. The Attempt at a Solution |z/u|=|(2 + i)/(-3-3i)| = |(2 + i)/(-3-3i)*(-3+3i/(-3+3i)| --- if it is not clear, I'm multiplying by the conjugate. = |(-6+6i-3i+3i^2)/(9-9i+9i-9i^2)|...
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