Question 0111b

Given that the curve with equation ${y=f(x)}$ passes through the points with coordinates ${(-2.6, 4.7),}$ ${(2.2, -4.0)}$ and ${(4.2, -5.7),}$ 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 an increasing function.