Find all solutions in [0,2pi): cos^2x-cosx=0

Question

Find all solutions in [0,2pi): cos^2x-cosx=0

Answer 1

Hi Paula,

 

cos^2x-cosx=0

cosx(cosx - 1) = 0

cosx = 0 or cos x - 1 = 0

if cosx = 0 then x = pi/2 and 3pi/2

if cosx = 1 then x = 0 and pi

Solution set is x = {0, pi/2, pi, 3pi/2}