The equation of the curve is
y=x4−6x3+13x2−10x+5On differentiating with respect to x, we get
dydx=4x3−18x2+26x−10dydx](1,3)=4−18+26−10=2
Thus, the slope of the tangent at (1,3) is 2. The equation of the tangent is given as:
y−3=2(x−1)⇒y−3=2x−2⇒y=2x+1
The slope of the normal at (1,3) is 1slopeofthetangentat(1,3)=−12
Therefore, the equation of the normal at (1,3) is given as;
y−3=−12(x−1)⇒2y−6=−x+1⇒x+2y−7=0 is the required equation.