2. | cos(ax) dx 3. [ x cos(x) dx 4. exp (x) dx 5. [2xexp(-ax)dx a>0 6. [sin (x)exp(-ax)dx a>0) 7. [cos(x)exp (-j2x) dx B. J cost (x)exp(-jan) dx 9. [x(t) at where x(t) is the function of t shown below