Can someone help me with this simplification?
6sin(3x)cos(3x)
I know this simplify to 3sin(6x) but how?
identity:
sin2x = 2sinxcosx
As I tell every student, perhaps if you used symbols in your formulae that are not likely to appear (and inevitably have different meanings) in the questions you have to answer, you will have much better luck .....
The double angle formula is $\displaystyle \sin(2A) = 2 \sin (A) \cos (A)$. What do you think A is equal to in your question ....?