Moderate -0.5 This is a straightforward application of the standard integral for 1/x with a linear substitution. Students need to recognize the reverse chain rule pattern (constant 6 matches the derivative of 2x+1), integrate to get 3ln|2x+1|, and evaluate between limits—all routine techniques for P2 level with no conceptual challenges beyond careful arithmetic to reach ln 125.
Question 2:
2 | Integrate to obtain form kln(2x+1) | M1
Obtain correct 3ln(2x+1) | A1
Use subtraction law of logarithms correctly | M1 | Dependent on first M1
Use power law of logarithms correctly | M1 | Dependent on first M1
Confirm ln125 | A1
5
Question | Answer | Marks | Guidance