The curves and intersect once in the first quadrant

MATHEMATICS · Single correct · AP · Calculus AB · Differentiation: Composite, Implicit, and Inverse Functions · Differentiation: Composite, Implicit, and Inverse Functions

Problem

The curves x2+y2=10x^{2}+y^{2}=10 and xy=5xy=5 intersect once in the first quadrant. The equation of their common tangent at that point is (a) x+y=25x+y=2\sqrt{5} (b) x+y=10x+y=\sqrt{10} (c) x−y=5x-y=\sqrt{5} (d) y=xy=x

Related theory

Browse the problem library