Date | November 2017 | Marks available | 3 | Reference code | 17N.1.sl.TZ0.14 |
Level | SL only | Paper | 1 | Time zone | TZ0 |
Command term | Find | Question number | 14 | Adapted from | N/A |
Question
A function f is given by f(x)=4x3+3x2−3, x≠0.
Write down the derivative of f.
Find the point on the graph of f at which the gradient of the tangent is equal to 6.
Markscheme
12x2−6x3 or equivalent (A1)(A1)(A1) (C3)
Note: Award (A1) for 12x2, (A1) for −6 and (A1) for 1x3 or x−3. Award at most (A1)(A1)(A0) if additional terms seen.
[3 marks]
12x2−6x3=6 (M1)
Note: Award (M1) for equating their derivative to 6.
(1, 4)ORx=1, y=4 (A1)(ft)(A1)(ft) (C3)
Note: A frequent wrong answer seen in scripts is (1, 6) for this answer with correct working award (M1)(A0)(A1) and if there is no working award (C1).
[3 marks]