The correct option is C √2
Given: Rectangular hyperbola x2−y2=22
To Find: Eccentricity
We know that, the eccentricity of a standard hyperbola is calculated using the equation,
e=√1+b2a2
Also, in a rectangular hyperbola, a=b.
⇒e=√1+a2a2
⇒e=√1+1=√2
This result implies that the eccentricity of a rectangular hyperbola remains √2 irrespective of the rectangular hyperbola equation.