All Flashcards
Define parametric equations.
Functions where independent functions x and y are connected via a parameter t.
What is a second derivative?
The derivative of the first derivative of a function.
What is ?
Notation for the second derivative of y with respect to x.
Define concavity.
The direction of the curve of a function (upward or downward).
What is a cycloid?
A curve traced by a point on a circle as it rolls along a straight line.
Define for parametric equations.
The first derivative of y with respect to x, found by .
What does the second derivative indicate?
The rate of change of the slope of a function; indicates concavity.
What is the quotient rule?
A rule for finding the derivative of a function that is the ratio of two other functions.
What is a parameter?
An independent variable (often denoted by 't') that relates two dependent variables.
What does it mean for a curve to be concave down?
The curve bends downwards, and its second derivative is negative.
Steps to find for , ?
- Find and . 2. Find . 3. Find . 4. Divide by .
How to determine where a parametric curve is concave up?
- Find . 2. Set . 3. Solve for t.
Find if and .
- , . 2. . 3. . 4. .
How to find the second derivative of and ?
- Find and . 2. Find . 3. Find . 4. .
Given and , show the cycloid is concave down.
- Find and . 2. Find . 3. Find . 4. Since the second derivative is always negative, the cycloid is always concave down.
How do you simplify ?
- Expand: . 2. Use : . 3. Simplify: .
What is the first step in finding the second derivative of , ?
Find the first derivatives: and .
How do you find the slope of the tangent line to a parametric curve at a specific t?
- Find . 2. Evaluate at the given value of t.
How do you find the t-values where a parametric curve has a horizontal tangent?
- Find . 2. Set and solve for t. 3. Ensure is not also zero at those t-values.
How do you find the t-values where a parametric curve has a vertical tangent?
- Find . 2. Set and solve for t. 3. Ensure is not also zero at those t-values.
Difference between finding and for parametric equations?
: Find . : Find the derivative of with respect to t, then divide by .
Concave up vs. concave down: second derivative sign?
Concave up: second derivative > 0. Concave down: second derivative < 0.
First derivative vs. second derivative: what do they tell us?
First derivative: slope of the tangent line. Second derivative: concavity.
Parametric equations vs. standard equations: how to find derivatives?
Parametric: use . Standard: direct differentiation with respect to x.
Finding horizontal vs. vertical tangents in parametric equations?
Horizontal: set . Vertical: set .
Quotient rule vs. chain rule: when to use them?
Quotient rule: derivative of a ratio. Chain rule: derivative of a composite function.
vs
is the rate of change of y with respect to x, while is the rate of change of x with respect to y. They are reciprocals of each other.
First derivative test vs. second derivative test
First derivative test: finds local max/min using sign changes of f'(x). Second derivative test: uses the sign of f''(x) to determine concavity and local extrema.
Explicit vs. implicit differentiation
Explicit: y is directly defined as a function of x (y = f(x)). Implicit: y is defined implicitly in terms of x (e.g., x^2 + y^2 = 1).
Local vs. global extrema
Local: max/min within a specific interval. Global: absolute max/min over the entire domain.