Unit 3: Composite & Implicit Differentiation
Calculus AB · Unit 3 · Paper 3

Composite & Implicit Differentiation unit test

A test on this unit alone, marked as a percentage and a letter grade — for the test your class is actually sitting, rather than for May. Answer everything, then submit once: seeing the answer to question 3 before attempting question 4 makes the final percentage meaningless.

Each paper is built from this unit’s 38 terms and is the same for everyone, so a teacher can assign “Unit 3, Paper 3” and every student sits the identical test. Multiple choice is marked objectively; the written sections you mark yourself against the model answer and rubric.
Suggested time 36 min 33 points0/17 attempted
1

Related rates as implicit differentiation

2

Vertical and horizontal tangents implicitly

3

The xy term needs the product rule

4

The lost inner factor

5

Derivative of a variable base with a variable exponent

6

Why dy/dx involves y

7

Sign of an implicit second derivative

8

Derivative of a variable base and exponent

9

Vertical tangent from an implicit derivative

10

Higher-order derivatives of sine

11

Where to evaluate an inverse derivative

12

Circle slope formula

Short answer 1. Define or explain: Implicit differentiation

3 pts

Short answer 2. Define or explain: Collect and factor

3 pts

Short answer 3. Define or explain: Derivative of an inverse function

3 pts

Short answer 4. Define or explain: Implicit second derivative sign

3 pts

Free response

9 pts

Consider the curve defined implicitly by x² + 2xy − y² = 7.

Show that the point (2, 1) lies on the curve, and find dy/dx in terms of x and y.

Write the equation of the line tangent to the curve at (2, 1).

Find the coordinates of all points on the curve at which the tangent line is vertical, and justify that the tangent is vertical rather than undefined for some other reason.