Given, parabola ⇒y2=6x⇒y2=4(23)x and given, line ⇒2x+y=1.∵ Equation of any tangent to the parabola having slope m is y=mx+2m3 Slope of line 2x+y=1 is m1=−2∵ Tangent is perpendicular to this line, ∴ Slope of tangent =m2=−m1=21∴ Equation of tangent will be y=21x+23×2y=2x+3 or2y=x+6 orx−2y+6=0 Clearly, on putting the coordinates of point (5,4), the equation of tangent is not satisfied. ∴ Point (5,4) does not lie on this tangent.