e^(3x) sin(4x) value of definite integral when a is pi/4 and b is 0

i get 4/25 * (e^(3pi/4)

how to simplify

There is not much to simplify.

Is the integration from a to b or from b to a?
Your answer is close, but has the wrong sign and missing a term.
Remember that e^0 is 1 and not zero.