Tangent lines using derivatives
Grade 12 Math Worksheet

Circle the best answer, or write your answer on the line.
Ari writes the tangent line to f(x) = 12/x at x = 3 as y = mx + b. What is b?
Bo writes the tangent line to f(x) = 20/x at x = 4 as y = mx + b. What is b?
Esme writes the tangent line to f(x) = −6/x at x = 3 as y = mx + b. What is b?
Jun writes the tangent line to f(x) = 15/x at x = 5 as y = mx + b. What is b?
Kira looks for every x where f(x) = x³ − 3x² − 9x + 5 has a horizontal tangent. List them, separated by commas.
Luz looks for every x where f(x) = x³ + 3x² − 24x + 1 has a horizontal tangent. List them, separated by commas.
Milo looks for every x where f(x) = x³ − 9x² + 15x has a horizontal tangent. List them, separated by commas.
Pia finds the tangent line to f(x) = (x + 1)/(x − 1) at x = 2. Which is it?
- y = −2x + 7
- y = −2x − 1
- y = −2x + 3
- y = 2x − 1
Tala finds the tangent line to f(x) = 4/(x² + 1) at x = 1. Which is it?
- y = −2x + 4
- y = −2x
- y = 2x
- y = −2x + 2
Zee finds the tangent line to f(x) = √(2x + 5) at x = 2. Which is it?
- y = (1/3)x + 11/3
- y = 3x − 3
- y = (1/3)x + 7/3
- y = (1/3)x + 3

