### Home > CALC > Chapter 4 > Lesson 4.4.3 > Problem4-153

4-153.

Find the linearization of $y = 4 − 2x^2$ at $(1, 2)$. Then, use it to approximate $y$ when $x = 1.15$.

Recall that you first investigated local linearization by using your calculator to 'zoom in' on a coordinate point until the curvy function appeared to be linear. You then found the equation of that 'line' using two points. You now have a better strategy.

Find the equation of the tangent line at $(1, 2)$ then evaluate $x = 1.15$.