Answer:
xy-1
Explanation:
Given expression is :
[tex]x^2-y^2=1[/tex] ..(1)
We need to find the value of [tex]\dfrac{dy}{dx}[/tex].
Differentiating equation (1) wrt x.
[tex]\dfrac{d}{dx}(x^2-y^2)=1\\\\2x-2y\times \dfrac{dy}{dx}=0\\\\2y\times \dfrac{dy}{dx}=2x\\\\y\times \dfrac{dy}{dx}=x\\\\\dfrac{dy}{dx}=\dfrac{x}{y}[/tex]
or
[tex]\dfrac{dy}{dx}=xy^{-1}[/tex]
Hence, the correct option is (c) "xy-1".