Find the equation of the tangent line to the graph of f at the given point.
-$$f ( x ) = 5 x ^ { 2 } + x \text { at } ( - 4,76 )$$
A) y = -39x - 80
B) y = -39x - 232
C) y = 10x
D) y = 10x + 1

Question

Quizplus · Accepted Answer

The derivative of f(x) is f'(x) = 10x + 1. So the slope of the tangent line at (-4,76) is f'(-4) = 10(-4) + 1 = -39. The equation of the tangent line is therefore y - 76 = -39(x + 4), or y = -39x - 80.

Find the Equation of the Tangent Line to the Graph f(x)=5x2+x at (−4,76)f ( x ) = 5 x ^ { 2 } + x \text { at } ( - 4,76 )f(x)=5x2+x at (−4,76)

Find the Equation of the Tangent Line to the Graph $f ( x ) = 5 x ^ { 2 } + x \text { at } ( - 4,76 )$