Home > Resources > Homework > Math > Unit Circle

Find the tangent line equations for every point on the unit circle

Answer 1

Abigail Nelson

Emily Hall

To find the tangent line equations for every point on the unit circle, we start with the unit circle equation:

$ x^2 + y^2 = 1 $

Differentiate implicitly with respect to $x$ to find the slope:

$ 2x + 2y \x0crac{dy}{dx} = 0 $

Solve for $ \x0crac{dy}{dx} $:

$ \x0crac{dy}{dx} = -\x0crac{x}{y} $

At a point $ (a, b) $ on the unit circle, the slope of the tangent is:

$ m = -\x0crac{a}{b} $

The tangent line equation at $ (a, b) $ is:

$ y – b = -\x0crac{a}{b}(x – a) $

Multiply through by $ b $ to get:

$ b(y – b) = -a(x – a) $

Simplify to obtain the final equation of the tangent line:

$ ax + by = 1 $

Answer 2

Alex Thompson

William King

To find the tangent line equations for every point on the unit circle, we start with the unit circle equation:

$ x^2 + y^2 = 1 $

Differentiate implicitly with respect to $x$ to find the slope:

$ 2x + 2y x0crac{dy}{dx} = 0 $

Solve for $ x0crac{dy}{dx} $:

$ x0crac{dy}{dx} = -x0crac{x}{y} $

At a point $ (a, b) $ on the unit circle, the slope of the tangent is:

$ m = -x0crac{a}{b} $

The tangent line equation at $ (a, b) $ is:

$ y – b = -x0crac{a}{b}(x – a) $

Answer 3

Amelia Mitchell

Henry Green

To find the tangent line equations for every point on the unit circle, we start with the unit circle equation:

$ x^2 + y^2 = 1 $

Differentiate implicitly with respect to $x$ to find the slope:

$ 2x + 2y x0crac{dy}{dx} = 0 $

Solve for $ x0crac{dy}{dx} $:

$ x0crac{dy}{dx} = -x0crac{x}{y} $

At a point $ (a, b) $ on the unit circle, the slope of the tangent is:

$ m = -x0crac{a}{b} $