Question

cos^2x-cos x=0

Answer 1

cos^2x-cos x=0
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Factor
cosx( cos x - 1) = 0
Zero Product Property
cos x = 0 OR cos x - 1 = 0
cos x = 0 or cos x = 1

Solve each equation for x.

Answer 2

@tjefiel What did you get for x?

Answer 3

pi/2 3pi/2 and pi

Answer 4

Are you supposed (see instructions) to solve the equation over the set of Reals or perhaps just [0, 2 pi] ?

Answer 5

[0,2pi]

Answer 6

I got {0, pi/2, 3pi/2, 2pi}

At x = pi, look what happens to the equation:

cos^2x-cos x=0
(cos pi)^2 - (cos pi) = (-1)^2 - (-1) = 1 + 1 = 2 which is not 0.

Answer 7

ahh my mistake i mixed them up thanks

Answer 8

Welcome.

Answer 9

one more thing, how well do you know how to solve a problem using line segments?