Solve the following differential equations:

a) dy/dx=24x(3x^2+9)^2

b) dy/dx=2sin(3x+infinity) infinity is a constant

I have done question (a) and got 216x^5+1296x^3+1944x as the answer. I don't know if this is correct.

I have no clue how to do (b).

Please help!!

Double-check your answer for a). A simple u-substitution will do the trick. For b), also a u-substitution ; let u = (3x + infinity).