k = 1
Explanation:Given the function:
[tex]f(t)=kt^2[/tex]The average rate of change is given by the formula:
[tex]R=\frac{f(b)-f(a)}{b-a}[/tex]where a = -1, b = 2
[tex]\begin{gathered} R=\frac{2^2k-(-1)^2k}{2-(-1)} \\ \\ =\frac{4k-k}{2+1} \\ \\ =\frac{3k}{3}=k \end{gathered}[/tex]Now, the rate of change has been given to be 1, so
[tex]R=k=1[/tex]