(a ) Evaluate the indefinite integral (anti-derivative) x2(1 + 23)6 d.x by using the substitution u = 1 + x3. Don't forget to add the constant of integra- tion. (b) Evaluate the indefinite integral tan' 0 sec2 do. Hint: look for a suitable substitution; in particular, whenever you spot an inte- grand of the form f(g(0) )g'(0), the substitution u = g(0) is likely helpful