Question

Rewrite with only sin x and cos x.

sin 3x - cos x

Answer 1

Hint: Expand sin3x by writing it as : sin(x+2x)

Answer 2

Recall 3x=2x+x
So sin(3x)=sin(x+2x)
Use the formula sin(u+v)=sin(u)cos(v)+sin(v)cos(u) to expand sin(x+2x)

Answer 3

i was thinking that but i wasnt sure

Answer 4

now all the options i am given have exponents in them how is that possible

Answer 5

That will be the case.
sin2x is 2sinxcosx.

Answer 6

i dont understand...