CAIE IGCSE Additional Math 1 Functions Topic Practice

$$\frac{3 \sqrt{x+2}}{\sqrt{x+2}+4}=1 \text { soi }$$

OR
$$g(x)=f^{-1}(1) \text { and } f^{-1}(x)=\frac{4 x}{3-x} \text { oe }$$

M1 for $\mathrm{f}(\sqrt{x+2})[=1]$ soi
or for
$\mathrm{g}(x)=\mathrm{f}^{-1}(1)$ soi

x=2 nfww

M1 FT for correct equation without an algebraic fraction e.g. $\sqrt{x+2}=2$

FT their $\frac{3 \sqrt{x+2}}{\sqrt{x+2}+4}=1$ providing M1 previously awarded and $\operatorname{fg}(x)$ is an algebraic fraction

Alternative method

Solves $\frac{3 x}{x+4}=1$ to find x=2 and states
g(x)=2

M1 for solving f(x)=1 to
find x=k and states
g(x)=k, where k is a
constant

x=2 nfww

M1 FT for $\sqrt{x+2}=k$
FT g(x)=k their providing
M1 previously awarded