Complex numbers allow us to come up with another solution method for several "complicated" integrals that involve sine, cosine, and exponential functions from Calculus 2.(a) This part is optional, but should be a good review for your Calc 2 knowledge. First, evaluate the following integrals using the materials you learned from Calc 2.(i)cos(3x)sin(x)dx(ii)e2xsin(x)dx(iii)excos2(x)dx(b) It can be shown that if f(x)=e(ai)x is a complex-valued exponential function, then ddx[e(aib)x]=(aib)ex and e(aib)xdx=1aibe(aib)xC. That is, the derivative and integral follow the same rule as with real-valued exponential function.In addition, we know that sine and cosine can be represented as cos(x)=eixe-ix2 and sin(x)=eix-e-ix2i, where x is a real number.Use these results to convert the sine and cosine functions in the three integrals from part (a) into complex exponential functions and evaluate those integrals.