# Help with inverse trig functions

vysero
Here is my problem:

cot(arcsin(x))

my awnser:

cot= x/(1-x)^1/2

The online program were suppose to use says im wrong but im not sure what I did wrong.

## Answers and Replies

Staff Emeritus
Homework Helper
Gold Member
Here is my problem:

cot(arcsin(x))

cot= x/(1-x)^1/2

The online program were suppose to use says im wrong but im not sure what I did wrong.
What's the question that you're trying to answer?

The answer you give makes no sense whatsoever.

Mentor
Draw a right triangle, with θ being the acute angle in the triangle. Let θ = arcsin(x), and label the sides and hypotenuse according to this definition.

The problem boils down to evaluating cot(θ).

Your answer SHOULD NOT start with "cot =" since cot by itself is meaningless in this context. If you are doing your work on paper, your work should start with cot(arcsin(x)) = ... and end up with what you found, which is actually not too far off.

The simplest way to do this is to imagine a right triangle with one angle $\theta$, "opposite side" to $\theta$ of length x, and hypotenuse of length 1 so that $sin(\theta)= x/1$ and thus $\arcsin(x)= \theta$.
Now, what is the length of the near side and what is $tan(\theta)= tan(arcsin(x))$?