3.3: Exponential inverse, sketch and composite equation

0606/12/F/M/24 — Question 4 · 11 marks

A function ff is such that f(x)=2+e3xf(x) = 2 + \mathrm{e}^{-3x}, xRx \in \mathbb{R}.
(a)
Write down the range of ff.
[1]
(b)
Find an expression for f1f^{-1}.
[2]
(c)
On the axes, sketch the graphs of y=f(x)y = f(x) and y=f1(x)y = f^{-1}(x), stating the coordinates of the points where the curves meet the coordinate axes. State the equations of any asymptotes. Label your curves.
[4]
(d)
A function gg is such that g(x)=x32+4g(x) = x^{\frac{3}{2}} + 4, x0x \geqslant 0.
Find the exact solution of the equation gf(x)=12gf(x) = 12.
[4]