Consider the curve defined by

MATHEMATICS · Single correct · CBSE · Mathematics · Continuity and Differentiability · Continuity and Differentiability

Problem

x^{2}+xy+y^{2}=7

. Determine the

x

-coordinate(s) where the curve has a horizontal tangent. (a)

x=\pm 2\sqrt{\dfrac{7}{3}}

(b)

x=\pm\sqrt{\dfrac{7}{3}}

(c)

x=\pm 1

(d)

x=0