Question 606190
cos^3x=cosx
This equation can be factored as cos(x)(cos^2(x) - 1) = 0
The RHS will be equal to 0 if either of the two factors is equal to 0.
So we have cos(x) = 0 and cos^2(x) - 1 = 0
cos(x) = 0 -> x = multiples of {{{pi/2}}}
cos^2(x) - 1 = 0 can be factored as (cos(x)+1)(cos(x)-1) = 0
This gives cos(x) = +/- 1 -> x = multiples of {{{pi}}}