Need help using scientific calculator

In summary, the conversation discusses various mathematical problems, including using a calculator to solve equations and simplifying expressions with exponents and roots. The conversation also highlights the importance of using correct terminology and understanding mathematical rules in order to avoid errors.
  • #1
physicsgal
164
0
-81^(1/4)
= -4square root sign 81
=-3

how do i key this into my calculator:
= "-4square root sign 81"

*note I am working with a $20 casio*

thanks

~Amy
 
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  • #2
(-)

81

^

0.25
 
  • #3
i see how to work it that way.. but i can't type in "-4square root sign 81", or is that not possible? (im just trying to follow how to do they do it in the book.. i realize both things lead to the right answer)

also

(49x^8y^-2z^6)^(1/2)
=7x^4y-1z^3
=7x^6 * (1/y) * z^3

where does the ^6 come from, or is that a typo in my lesson book?

~Amy
 
  • #4
It depends if your calculator has DAL or not. With an old style calculator, you'd need to enter "8, 1, +/-, y^x, (, 1, /, 4, ), =", with a DAL one you'd enter "-, 8, 1, y^x, (, 1, /, 4, ), =".
 
  • #5
ok

here's another one 9,765,625 = 5^n
n = ?

*n = 10*.. but how would i have figured this out using my calculator?

~Amy
 
  • #6
That requires the use of the "log" button.

n = log 9765625 / log 5
n = 10
The generalization of this rule is...

If ... x^n = y,
Then ... n = log y / log x.​
This is taught in Grade 12 where I live, so I can assume that you don't need to worry about why or how.
 
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  • #7
thank you! it works. funny the lesson book doesn't mention log calculations.

~Amy
 
  • #8
Please, please, please! Do NOT use "4 square root" for fourth root. It confuses you as well as the people you are talking to (and has been known to cause some math teachers to foam at the mouth).
 
  • #9
Please, please, please! Do NOT use "4 square root" for fourth root. It confuses you as well as the people you are talking to (and has been known to cause some math teachers to foam at the mouth).
thanks, i ll try to remember.

here's one involving exponents.. is my answer in the lowest term or is there more that could be done?

((2^-3 + 5^0)/ (2^-5))^(1/2)

= ((9/8)^(1/2))/ (1/32)

~Amy
 
  • #10
Not at all, you can reduce it completely. Also, your second step is incorrect as you forgot to square root the denominator. Here's my solution:

[tex]\begin{equation*}
\begin{split}
(\frac{2^{-3} + 5^{0}}{2^{-5}})^{\frac{1}{2}} &= \frac{\frac{9}{8}^{\frac{1}{2}}}{\frac{1}{32}^{\frac{1}{2}}}\\
\\
&= (\frac{3}{\sqrt{8}}) (\frac{\sqrt{32}}{1})\\
\\
&= \frac{3\sqrt{4}\sqrt{8}}{\sqrt{8}}\\
\\
&= 6
\end{split}
\end{equation*}[/tex]
 
Last edited:
  • #11
thanks. i did it 'the amy way' and got the same answer. just converted the numbers to normal numbers (1.125/0.03125)^(1/2).

also, is there any way to convert this to something like this: (so you can just figure it out be crossing out the like numbers):

[((1/2)(1/2)(1/2) + 1)/ ((1/2)(1/2)(1/2)(1/2)(1/2))] ^ (1/2)

= [1/(1/2)(1/2)]^(1/2)??

with that i end up with = 2. why is that method not working??

~Amy
 
  • #12
No... [itex]\frac{a + b}{(a)(c)}[/itex] is not the same as [itex]\frac{b}{c}[/itex]. Although that's what your solution suggests; you cancel out the (1/2), even though you have two separate terms in the numerator. It doesn't make sense to be able to cancel out the a's when their weight on the equation is inequivilent.

I suggest that you practice simplifying these algebraic equations (as I showed in my last post), learn the rules of Math, and prevent yourself from following these techniques blindly. If you don't fix your presumptious tuitions of what you can do to an equation, you're going to run into some painful potholes down the rode.
 
Last edited:
  • #13
thanks for the tips. i somewhat see what you're saying. i should go over my lesson books again. I am doing this as a study-at-home course so that's part of the problem (me teaching myself) :yuck:

i appreciate the help.

~Amy
 

1. How do I enter numbers and equations into a scientific calculator?

To enter numbers, simply use the numerical keys on the calculator. For equations, use the appropriate mathematical symbols such as +, -, x, and /. You can also use parentheses to indicate the order of operations.

2. How do I switch between degrees and radians on a scientific calculator?

Most scientific calculators have a button labeled "DRG" or "DEG/RAD" which allows you to switch between degrees and radians. If you're unsure, refer to the user manual for your specific calculator.

3. What is the "EXP" or "EE" button on a scientific calculator for?

The "EXP" or "EE" button is used for entering numbers in scientific notation. For example, to enter 1.5 x 10^5, you would press 1.5, then the "EXP" or "EE" button, and then 5.

4. How do I use the memory function on a scientific calculator?

To store a number in the calculator's memory, press the "STO" or "MS" button, followed by the memory location you want to store it in (usually labeled with a letter). To recall a number from memory, press "RCL" or "MR" followed by the memory location.

5. What is the difference between a scientific calculator and a graphing calculator?

A scientific calculator is designed for basic mathematical calculations and scientific functions, while a graphing calculator has more advanced capabilities such as graphing equations and performing statistical analysis. A graphing calculator is typically more expensive and has a larger screen than a scientific calculator.

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