MathematicsEasy175×since 2002Q2790The number of points on the curve y=54x5−135x4−70x3+180x2+210xy=54 x^{5}-135 x^{4}-70 x^{3}+180 x^{2}+210 xy=54x5−135x4−70x3+180x2+210x at which the normal lines are parallel to x+90y+2=0x+90 y+2=0x+90y+2=0 is :A2B3C4D0Check answerSkip