The required point is?

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1 Answer
Mar 15, 2018

Answer is (4).

Explanation:

Let us find the slope of tangent on curve #x^2y^2-2x=4(1-y)# at point #(2,-2)#, which is given by its derivative at the point. Derivative is given by

#2xy^2+2x^2y(dy)/(dx)-2=-4(dy)/(dx)#

i.e. #(dy)/(dx)=(2(1-xy^2))/(2(x^2y+2))=(2(1-2*(-2)^2))/(2(2^2*(-2)+2))=7/6#

and equation of tangent is #y+2=7/6(x-2)# or #6y-7x+26=0# or #y=(7x-26)/6#

It can be easily seen that while #(4,1/3),(8,5)# and #(-4,-9)# lie on tangent, #(-2,-7)# does not lie on tangent.

Hence answer is (4).