### Home > CALC > Chapter 7 > Lesson 7.1.1 > Problem7-6

7-6.

$\text{The derivative of ln}(x)=\frac{1}{x}.$

Chain Rule.

$\frac{d^{2}y}{dx^{2}}=\frac{d}{dx}\text{(answer to part (a)) }.$

The equation for the tangent line is yy(3) = y'(3)(x − 3).

Implicit Differentiation.

$\text{Implicit differentiation. Solve for }\frac{dy}{dx}.$

Translation: Evaluate the 2nd-derivative (that you found in part (e)) at x = 3.

Is the graph concave up or concave down?