Trigonometry Functions help (AS Level)

Please could you help me with this question.

sin^(2)x = 1-cosx

Thank you.

You're on the right track with 1 - cos(^2)x = 1 - cosx, so I'll show you what to do from there:

First collect all the terms on one side so it's equal to zero:

cos(^2)x - cos(x) = 0

Now you can treat it like a quadratic equation. Let cos(x) = u, for example:

u^2 - u = 0

Much easier to solve - you get u = 0 and u = 1

So put the cos(x) back in, and you get:

cosx = 0
cosx = 1

Just solve these using the cos^-1 button on your calculator to find the answers within whatever boundaries you have been given. Don't be worried if you end up with several possible answers!

:)

What do you need to do with it?
Either way, check out this link. It might help you :)

http://www.wolframalpha.com/input/?i=sin…