y2=4xP(1,2),Q(14,1)
Slope of PQ=1−214−1=43
Slope of tangent =43
Equation of tangent in slope form is y=mx+am
a=1
y=43x+143y=43x+3412y=16x+9....(i)16x=12y−94x=12y−94
Substituting in the equation of parabola
y2=12y−944y2=12y−94y2−12y+9=0(2y−3)2=0⇒y=32(32)2=4x⇒x=916
So the point R is (916,32)
Option (B) is correct.