Equation of a Circle and Finding the Tangent

The video tutorial covers the equation of a circle, starting with the basic formula x^2 + y^2 = r^2. It explains how to find the radius from the equation and provides examples. The tutorial then demonstrates using Pythagoras' theorem to calculate the radius and equation of a circle. Finally, it explains how to find the equation of a tangent to a circle, including calculating gradients and using the negative reciprocal for perpendicular lines.

What is the relationship between the gradient of the radius and the gradient of the tangent?

Describe the steps to find the equation of a tangent line to a circle at a given point.