Question

Write the expression as one
involving only sin x and cos x.
sin 2x + cos x

Answer 1

sin 2x + cos x = 2 sin x cos x + cos x = (2 sin x + 1)cos x

Explanation:

Given the expression: sin 2x + cos x,

then we can use the formula: sin 2x = 2 sin x cos x, which gives:

sin 2x + cos x = 2 sin x cos x + cos x = (2 sin x + 1)cos x

So there you have two expressions in terms of sin x and cos x, as requested. :D