Let $f(x)=2x+3$ and $g(x)=x^2$.
(a) Find $(f\circ g)(2)$. [2]
(b) Find $f^{-1}(x)$. [2]
- $g(2)=4$ then $f(4)$M1
- $11$A1
- Sets $y=2x+3$ and rearranges for $x$ (or swaps and rearranges)M1
- $f^{-1}(x)=\dfrac{x-3}2$A1
- Answer: (a) $11$ (b) $\dfrac{x-3}{2}$
- Examiner tip: $(f\circ g)(x)$ means apply $g$ first, then $f$.