use a double angle formula to rewrite the expression : 6sinxcosx?

Answer 1

Remember that sin2x = 2 sinx cosx

Then

6 sinx cosx

= 3 ( 2 sinx cosx)

= 3 sin2x

~The C~

Answer 2

That's 3*2 sin x cos x = 3*sin 2x because
Sin 2x = 2 sin x cos x.