Question

find the solution of the equation in the interval notation[0,2pi) cos^3= cos x

Answer 1

well rewrite the equation as

\[\cos^3(x) - \cos(x) = 0\]

factoring you get

\[\cos(x)(\cos^2(x) - 1) = 0\]

factor the quadratic and you should be then able to identify all the solutions..

Answer 2

can u pls check my answer, is x=pi,x=pi/2,x=3pi/2

Answer 3

well you should have found

cos(x) = -1, 0 and 1

so the inverse are 0, pi/2, pi, 3pi/2

Answer 4

your awesome. thank you.