## 6532bunny Group Title Verify the identity. sin (4u) = 2 sin (2u) cos (2u) Please help, verifying these kind of equations is tricky for me. one year ago one year ago

1. slaaibak Group Title

Hmm. you can try doing it like this: sin(2u + 2u) = sin(2u) * cos(2u) + cos(2u) * sin(2u) = 2sin(2u)*cos(2u) Note: I referred to: sin(A + B) = sinAcosB + cosAsinB

2. 6532bunny Group Title

Oh, I see. Is that the final answer?

3. 6532bunny Group Title

I mean, is that it? Usually these questions take up more space. >_<

4. slaaibak Group Title

I'm pretty sure it is, yes

5. AravindG Group Title

you can also use the identity that $\bf \large \boxed{\sin 2A= 2\sin A \times \cos A }$

6. AravindG Group Title

treating $4u=2 \times (2u)$