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

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 y - 76 = -39(x + 4), which simplifies to y = -39x - 80.

Find the Equation of the Tangent Line to the Graph f(x)=5x2+xf ( x ) = 5 x ^ { 2 } + xf(x)=5x2+x

Find the Equation of the Tangent Line to the Graph $f ( x ) = 5 x ^ { 2 } + x$