4. First complete the square, make the appropriate substitutions, and then evaluate the integral: 1 dx - 2x +5 5. Evaluate each of the following integrals, using the given substitution or identity. Solutions using other methods are not acceptable. (a) fcos' xsin xax (substitution u = sinx ) 14 (b) Jo tan'xsec xdx (substitution u = tan x ) (c) [sin(5x) sin(3x) dx sin( A) sin( B) = = [cos(A - B) - cos(A + B)] (d) Scos(6x) cos(4x) dx COS( A) cos( B) = - [cos(A - B) + cos( A + B)]