Use the substitution u=x2+13u = x^2 + 13u=x2+13 to find ∫2xx2+13dx\displaystyle \int \frac{2x}{x^2 + 13} dx∫x2+132xdx
119 exam-style questions on CCEA A Level Maths 3.6.4 Integration (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.