1. ## inverse trigonometry

i was wondering how I would approach proving this problem
sin ^-1(x) + cos ^ -1 (x) = pi/2

2. ## Re: inverse trigonometry

You could solve it numerically.

Or you could take guesses for x. i.e $x = \frac{1}{\sqrt{2}}$

3. ## Re: inverse trigonometry

WTS:

$\sin^{-1}(x)+\cos^{-1}(x)=\frac{\pi}{2}.$ True if and only if (assuming all the domains are worked out correctly):

$\sin^{-1}(x)=\frac{\pi}{2}-\cos^{-1}(x),$ iff

$x=\sin\left(\frac{\pi}{2}-\cos^{-1}(x)\right)=\dots$

Can you see your way forward?