Date | May 2019 | Marks available | 3 | Reference code | 19M.2.SL.TZ2.T_5 |
Level | Standard Level | Paper | Paper 2 | Time zone | Time zone 2 |
Command term | Find | Question number | T_5 | Adapted from | N/A |
Question
Consider the function f(x)=13x3+34x2−x−1.
Find f′(x).
Find the gradient of the graph of y=f(x) at x=2.
Find the equation of the tangent line to the graph of y=f(x) at x=2. Give the equation in the form ax+by+d=0 where, a, b, and d∈Z.
Markscheme
x2+32x−1 (A1)(A1)(A1)
Note: Award (A1) for each correct term. Award at most (A1)(A1)(A0) if there are extra terms.
[3 marks]
22+32×2−1 (M1)
Note: Award (M1) for correct substitution of 2 in their derivative of the function.
6 (A1)(ft)(G2)
Note: Follow through from part (d).
[2 marks]
83=6(2)+c (M1)
Note: Award (M1) for 2, their part (a) and their part (e) substituted into equation of a straight line.
c=−283
OR
(y−83)=6(x−2) (M1)
Note: Award (M1) for 2, their part (a) and their part (e) substituted into equation of a straight line.
OR
y=6x−283(y=6x−9.33333…) (M1)
Note: Award (M1) for their answer to (e) and intercept −283 substituted in the gradient-intercept line equation.
−18x+3y+28=0 (accept integer multiples) (A1)(ft)(G2)
Note: Follow through from parts (a) and (e).
[2 marks]