# Math Help - inverse trig squaring

1. ## inverse trig squaring

By squaring both sides of y=sincos^-1 (x) and using the identity sin^2 x + cos^2 x = 1. Show that y=Sqrt(1-x^2)

I'm not sure how to square an inverse function.

Thannk you

2. Originally Posted by deltaxray
By squaring both sides of y=sincos^-1 (x) and using the identity sin^2 x + cos^2 x = 1. Show that y=Sqrt(1-x^2)

I'm not sure how to square an inverse function.

Thannk you
Whenever you have an inverse function, you should give it a name. That helps. Let us call $\cos^{-1} (x)$ as $\theta$. This means $\cos \theta = x$.
Now let us read your question. You know that $y = \sin\cos^{-1} x = \sin \theta$

Now can you write $\sin \theta$ in terms of $\cos \theta$ and finish the problem?

Do not forget to substitute the variable $\theta$ back.

3. thank you

I got it