Question

Verify the identity.
sin 4u = 2 sin 2u cos 2u

Answer 1

A rule of thumb for something like this is to always start on the side that seems the most complicated

Answer 2

2cos(x) sin(x) = 2sin(2x)

use that

Answer 3

I'm really bad at these..

Answer 4

Use sourwing 's equation to help you since that is a trig identity that really helps

Answer 5

I'm not sure what to do next

Answer 6

..sin(4u)
= sin(2u+2u)
= sin(2u)cos(2u) + cos(2u)sin(2u)
= 2 sin(2u) cos(2u). ?

Answer 7

2 cos(2u) sin(2u) = 2 sin(2 * 2u) = 2 sin(4u)

Answer 8

yes, you can do it that way