Tangent lines

Use the derivative to write the equation of the tangent at a point and to approximate values.

Standards:AP Calc AB · Unit 2AP Calc AB · Unit 4

Try it: three questions

Real questions from the practice bank. Tap an answer to check it.

Question 1 of 3

A line is tangent to the circle x² + y² = 25 at the point (3, 4). What is the slope of this tangent line?

Question 2 of 3

A line is tangent to the circle at point P. The radius to P is 5 cm and makes a 35° angle with the horizontal. What is the angle between the tangent line and the radius?

Question 3 of 3

A circle has center O and radius 5 cm. Point P is outside the circle, 13 cm from O. A line from P is tangent to the circle at point T. Find the length of PT.

How this fits in

Tangent lines is one skill in the Intro to Calculus unit. Students read the unit lesson, then earn a bronze, silver, or gold medal on their last 10 answers. Medals never go down. A mastered unit comes back for review after 1, 3, 7, 16, and 35 days so it stays learned.

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