If 2x-y+1=0 is a tangent to the hyperbola x2a2-y216=1, then which of the following cannot be sides of a right angled triangle [2017]
(1, 2, 3)
Given 2x-y+1=0 i.e. y=2x+1 is a tangent to hyperbola x2a2-y216=1
∴ c2=a2m2-b2
⇒12=a2×22-16
⇒a2=174⇒a=172
∴ a,4,1; a,4,2; 2a,8,1 i.e. 172,4,1; 172,4,2; 17,8,1 cannot be the sides of a right triangle.