help plz :) (1 Viewer)

[mystify]

Hey evry1 i was hopin dat sum1 can help me with this question:

sin(^2)2x + cos2x = 1 (that reads: sine squared 2x + cos2x)

solve for 'x' between the domain zero and pie

Any help would be greatly appreciated thnx in advance....

 

[withoutaface]

You change the sin²2x to 1- cos²2x

so you have 1-cos²2x+cos2x=1
0=cos²2x-cos2x
0=cos2x(cos2x-1)

so :. cos2x=0_________OR cos2x=1
2x=pi/2, 3pi/2 ______________0, pi, 2pi

x=pi/4, 3pi/4, 0, pi/2, pi

Hope that helps

 

[mystify]

Thanx!

Thnx alot....u make it seem so ezy!