SOLUTION: What are the x's of: 2cos^2(x)+3cos(x)=0

Algebra ->  Trigonometry-basics -> SOLUTION: What are the x's of: 2cos^2(x)+3cos(x)=0      Log On


   

Question 750779: What are the x's of: 2cos^2(x)+3cos(x)=0
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
What are the x's of:
2cos^2(x)+3cos(x)=0
0 ≤ cos(x) ≤ 2π
2cosx(cosx+3)=0
2cosx=0
x=π/2, 3π/2
cosx+3)=0
cosx=-3 (reject, not in domain)