How to denote the second derivative of a function?
$f''(x)$ or $\frac{d^2y}{dx^2}$
Formula to find critical points?
$\frac{dy}{dx} = 0$ or $\frac{dy}{dx}$ is undefined
How to express implicit differentiation?
$\frac{d}{dx} [F(x, y)] = 0$
Formula for the first derivative test?
If $f'(x)$ changes from positive to negative at $x=k$, then $f(x)$ has a relative maximum at $x=k$. If $f'(x)$ changes from negative to positive at $x=k$, then $f(x)$ has a relative minimum at $x=k$.
Formula for the second derivative test?
If $f''(x) > 0$, then $f(x)$ is concave up. If $f''(x) < 0$, then $f(x)$ is concave down.
How to express the derivative of $x^2 + y^2 = 25$ with respect to x?
$2x + 2y \frac{dy}{dx} = 0$
How to find $\frac{dy}{dx}$ for $x^2 + y^2 = 4$?
Differentiate both sides: $2x + 2y\frac{dy}{dx} = 0$. Solve for $\frac{dy}{dx}$: $\frac{dy}{dx} = -\frac{x}{y}$.
Steps to find critical points for $x^2 + y^2 = 16$?
1. Find $\frac{dy}{dx}$. 2. Set $\frac{dy}{dx} = 0$ and undefined. 3. Solve for x and y.
How to determine if $(0, 4)$ is a local max/min for $x^2 + y^2 = 16$?
1. Find $\frac{dy}{dx}$. 2. Evaluate $\frac{dy}{dx}$ around $(0, 4)$. 3. Check for sign change.
How to find $\frac{dy}{dt}$ given $\frac{dx}{dt} = 3$ for $x^2 + y^2 = 25$?