How do you put in code on C++ [(cos^-1) which is found on calculators as shift cos]...

what I am trying to do is solve for theta...

cos (theta) = Fy/Fx

how would i put that in code?

This is a discussion on *How do...* within the **C++ Programming** forums, part of the General Programming Boards category; How do you put in code on C++ [(cos^-1) which is found on calculators as shift cos]...
what I am ...

- 02-09-2005 #1

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## How do...

How do you put in code on C++ [(cos^-1) which is found on calculators as shift cos]...

what I am trying to do is solve for theta...

cos (theta) = Fy/Fx

how would i put that in code?

- 02-09-2005 #2
use the acos() function

If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.

If at first you don't succeed, try writing your phone number on the exam paper.

- 02-09-2005 #3

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Do you have an IDE, like Borland CBuilder, MS Visual C++, or anything to that effect? If so, usually you can use the help function to search when you're just looking for a function.

Searching cos would probably yield acos as an alternate result.

- 02-09-2005 #4

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I use acos() but, it does not calculate properly

- 02-09-2005 #5

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Are you assigning it to an integer variable? Make sure you're using a float.

- 02-09-2005 #6

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Originally Posted by**MyDestiny**

- 02-09-2005 #7

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what do u mean float?

i didn't assign it to anything

- 02-09-2005 #8

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I keep getting...

-1.#IND

as my answer

- 02-09-2005 #9

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What are you doing with it?

You either need to use it in an expression or assign it to a variable.

float accepts decimal values. Integers, as you know, cannot - int in C++ is the same as a real-life integer where no decimal values are allowed

- 02-09-2005 #10

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## Radians?

All of the trig functions in <cmath> use radians, not degrees. Maybe that will help. (?)

- 02-09-2005 #11
Example

Code:#include<stdio.h> #include<math.h> int main(){ double angle = 0.5; /* this is in radians */ double c = cos( angle ); double d = acos( c ); printf( "%f %f %f\n", angle, c, d ); return 0; }

If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.

If at first you don't succeed, try writing your phone number on the exam paper.

- 02-09-2005 #12

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All of the trig functions in <cmath> use radians, not degrees. Maybe that will help. (?)

I think MyDestiny might be using integer containers but it's hard to say without seeing the code

- 02-10-2005 #13

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I just wanted to let you all know that I figured out the answer... THANKS a bunch for your help!

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