Find the equation of the tangent and normal to the given curve at the given points
y=x4−6x3+13x2−10x+5 at (1,3)
The equation of the given curve is,
y=x4−6x3+13x2−10x+5
On differentiating w.r.t. x, we get dydx=4x3−18x2+26x−10
∴ Slope of tangent at (1,3) is (dydx)(1,3) =14-18+26-10=2
Thus, the slope of the tangent at (1,3) is 2. Now, the equation of the tangent is
y−3=2(x−1)⇒y−3=2x−2⇒y=2x+1
Again, the slope of normal at (1,3) is
−1Slope of tangent at (1,3)=−12
Hence, the equation of the normal at (1,3) is
y−3=−12(x−1)⇒2y−6=−x+1⇒x+2y−7=0