As shown in the pre-class video, the indefinite integral dx I = / (x2 - 12x + 40)2 can be evaluated as following: (1) Complete the square for the quadratic x2 - 12x + 40 = (x - a)2 + b2 and then make the substitution x - a = b tan 0 where a = 6 b = 2 (2) Write the integrand in terms of 0 to obtain I = / f(0)de = 8(0) + C where f(0) = and g(0) = Now, we may calculate the integral in function of x to obtain I = +C Your last answer was interpreted as follows