Question 0111b

Given that the curve with equation ${y=f(x)}$ passes through the points with coordinates ${(-1.7, -1.7),}$ ${(2.3, 4.3)}$ and ${(4.8, 18.0),}$ find the values of ${a,b}$ and ${c.}$ Give your answers correct to 3 decimal places.

Find the set of values of ${x}$ for which ${f(x)}$ is a decreasing function.