SOLUTION: solve the equation: sin x(sin x + 1) = 0 4 cos^2 x - 1 = 0

Algebra ->  Trigonometry-basics -> SOLUTION: solve the equation: sin x(sin x + 1) = 0 4 cos^2 x - 1 = 0      Log On


   

Question 924584: solve the equation:
sin x(sin x + 1) = 0
4 cos^2 x - 1 = 0
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi, Previously Posted

sin x(sin x + 1) = 0 

sin^2 x + sinx = 0

sin^2x = - sinx

sinx = -1

....

4 cos^2 x - 1 = 0

cos^2 x = 1/4

cosx  = ± 1/2

....

refer to (cosx, sinx) Summary Unit Circle for corresponding x-values

.