Date | May Specimen paper | Marks available | 2 | Reference code | SPM.1.SL.TZ0.5 |
Level | Standard Level | Paper | Paper 1 (without calculator) | Time zone | Time zone 0 |
Command term | Show that | Question number | 5 | Adapted from | N/A |
Question
The functions f and g are defined such that f(x)=x+34 and g(x)=8x+5.
Show that (g∘f)(x)=2x+11.
[2]
a.
Given that (g∘f)−1(a)=4, find the value of a.
[3]
b.
Markscheme
attempt to form composition M1
correct substitution g(x+34)=8(x+34)+5 A1
(g∘f)(x)=2x+11 AG
[2 marks]
a.
attempt to substitute 4 (seen anywhere) (M1)
correct equation a=2×4+11 (A1)
a = 19 A1
[3 marks]
b.
Examiners report
[N/A]
a.
[N/A]
b.