Students learn how to find the equation of a tangent to a curve and circle.

Later, as learning progresses they apply their learning to prove whether a line is tangential.

**Differentiated Learning Objectives**

- All students should be able to calculate the gradient of a tangential line to a circle.
- Most students should be able to calculate the equation of a line tangential to a circle.
- Some students should be able to use algebra to prove a line is tangential to a circle.