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.

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