Question

rewrite with only sinx and cosx. sin3x+cos3x

Answer 1

ooh^ this is so exciting!

Answer 2

Use the identities for the sin and cos of the sum of two angles, with the two angles being x and 2x. Then use the identities for the sin and cos of 2x to turn it all into sin and cos of x

Answer 3

are you familiar withthe expansion for something of the form \(cos3\theta\)

Answer 4

handy trig identity table at http://www.sosmath.com/trig/Trig5/trig5/trig5.html