Find the equation of the line tangent to the graph of f at the indicated value of x.
-f(x) = 5 ln x; x = 1
A) y = 5x - 1
B) y = 5x + 5
C) y = 5x
D) y = 5x - 5

Question

Quizplus · Accepted Answer

The derivative of f(x) = 5 ln x is f'(x) = 5/x. At x = 1, f'(1) = 5. The point on the graph is (1, f(1)) = (1, 0). The equation of the tangent line is y - 0 = 5(x - 1), which simplifies to y = 5x - 5.

Find the Equation of the Line Tangent to the Graph