Show that the tangent to the circle is horizontal at the points and

MATHEMATICS · Subjective · A Level · Mathematics · Differentiation · Differentiation

Problem

Show that the tangent to the circle

x^{2}+y^{2}=9

is horizontal at the points

(0,3)

and

(0,-3)

. Give a brief reason based on the value of

\frac{dy}{dx}

at these points.