Consider the function 𝑅𝑡=−𝑡2−7𝑡+5
Find 𝑅−1 and 𝑅2
Find the average rate of change of 𝑅 over the interval −1≤𝑡≤2 
Apply that average rate of change to estimate 𝑅1.6.
Without actually finding 𝑅1.6, can we predict whether our estimate is an overapproximation or underapproximation?