Complete the square:Complete the square for the denominator x2−8x+65 to make it look like (x−h)2+k2, which is suitable for a trigonometric substitution.(x2−8x+16)+49=(x−4)2+72
Recognize standard form: Recognize that the integral is now in the form of ((x−h)2+k2)1, which is a standard form for arctan substitution.
Use substitution u: Use the substitution u=7x−4, then du=71dx.
Rewrite integral in terms: Rewrite the integral in terms of u: ∫u2+11⋅7du.
Integrate using arctan formula: Integrate using the arctan formula: ∫u2+11du=arctan(u)+C.
Substitute back for x: Substitute back for x to get the final answer: (71)arctan(7(x−4))+C.
More problems from Find derivatives of using multiple formulae