Date | November 2015 | Marks available | 6 | Reference code | 15N.1.sl.TZ0.3 |
Level | SL only | Paper | 1 | Time zone | TZ0 |
Command term | Find | Question number | 3 | Adapted from | N/A |
Question
Let \(f'(x) = 6{x^2} - 5\). Given that \(f(2) = - 3\), find \(f(x)\).
Markscheme
evidence of antidifferentiation (M1)
eg\(\;\;\;f = \int {f'} \)
correct integration (accept absence of \(C\)) (A1)(A1)
\(f(x) = \frac{{6{x^3}}}{3} - 5x + C,{\text{ }}2{x^3} - 5x\)
attempt to substitute \((2,{\text{ }} - 3)\) into their integrated expression (must have \(C\)) M1
eg\(\;\;\;2{(2)^3} - 5(2) + C = - 3,{\text{ }}16 - 10 + C = - 3\)
Note: Award M0 if substituted into original or differentiated function.
correct working to find \(C\) (A1)
eg\(\;\;\;16 - 10 + C = - 3,{\text{ }}6 + C = - 3,{\text{ }}C = - 9\)
\(f(x) = 2{x^3} - 5x - 9\) A1 N4
[6 marks]