Question

Find all solutions to the equation in the interval [0, 2π).

cos 2x - cos x = 0

Answer 1

Where might cos(2x) = cos(x)?

Answer 2

quad 4?

Answer 3

Do you know what a cos graph looks like from 0 to 2pi?

Answer 4

no ;/

Answer 5

these are my choices btw
0, two pi divided by three., four pi divided by three

pi divided by six., five pi divided by six, three pi divided by two.

0, pi divided by two., seven pi divided by six, eleven pi divided by six

No solution

Answer 6

Forget about the choices. Understanding what a cos graph looks like will help you out a lot.

baring my inability to draw lines, that is a cos graph.