# Trigonometric equation.

Printable View

• Mar 6th 2011, 10:41 PM
helpwouldbenice
Trigonometric equation.
Hi i'm currently on Trigonometric equations.
I got stuck on one particular math problem.
It's the following problem

Sin(x*pi/2)=cos(x*pi/2)+1

-2<= x <=2

I have tried over and over again but i can't solve it...
so if some kind sperit could give me some input on how to solve it, and what method to use it would be nice (Nod)

Sorry for my bad english....
and thank you in advance(Wink)
• Mar 6th 2011, 11:00 PM
Prove It
Square both sides to get

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

then apply the Pythagorean Identity to get this into a quadratic equation in terms of $\displaystyle \cos{\left(\frac{\pi}{2}x\right)}$, which you can then solve.

Of course, to avoid extraneous solutions, you will also need to draw an accompanying graph of your original function.
• Mar 6th 2011, 11:14 PM
helpwouldbenice
Cool! Now it was easy thank you for your help Prove it