Date | May 2014 | Marks available | 7 | Reference code | 14M.2.sl.TZ1.7 |
Level | SL only | Paper | 2 | Time zone | TZ1 |
Command term | Find | Question number | 7 | Adapted from | N/A |
Question
Let f(x)=g(x)h(x)f(x)=g(x)h(x), where g(2)=18, h(2)=6, g′(2)=5, and h′(2)=2. Find the equation of the normal to the graph of f at x=2.
Markscheme
recognizing need to find f(2) or f′(2) (R1)
f(2)=186 (seen anywhere) (A1)
correct substitution into the quotient rule (A1)
eg 6(5)−18(2)62
f′(2)=−636 A1
gradient of normal is 6 (A1)
attempt to use the point and gradient to find equation of straight line (M1)
eg y−f(2)=−1f′(2)(x−2)
correct equation in any form A1 N4
eg y−3=6(x−2), y=6x−9
[7 marks]
Examiners report
[N/A]