### Home > APCALC > Chapter 7 > Lesson 7.3.4 > Problem 7-145

7-145.

Write the equation of a line tangent to the graph of at

Use the tangent line to approximate the value of

.Because

is hard to evaluate, the tangent line atwill give a decent approximation of .Is your approximation an overestimate or an underestimate? Use the second derivative to justify your answer.

and that will indicate if the tangent line is above or below the graph.