Question

cos3x=cos^3(x)-3sin^2(x)Cos(x)

Answer 1

could you use the Equation editor instead, it's not very clear above with the powers?

Answer 2

\[\cos 3x=\cos ^{3}x-3\sin ^{2}x \cos x\]

Answer 3

what's required? simplify or find x?

Answer 4

prove idenity

Answer 5

cos(3x) = cos(2x + x) = cos(2x)cos(x) - sin(2x)sin(x) = [cos(x)^2 - sin(x)^2] * cos(x) - 2sin(x)cos(x)sin(x) =
cos(x)^3 - sin(x)^2 * cos(x) - 2sin(x)^2 * cos(x) =
cos(x)^3 - 3sin(x)^2 * cos(x)