1.

If `y=sqrt(((x-3)(x^(2)+4))/((3x^(2)+4x+5)))`, find `(dy)/(dx)`.

Answer» Given : `y=sqrt(((x-3)(x^(2)+4))/((3x^(2)+4x+5))).`
Taking logarithm on both sides of (i), we get
`logy=(1)/(2){log(x-3)+log(x-3)+log(x^(2)+4)-log(3x^(2)+4x+5)}.`
Differentiating both sides w.r.t. x, we get
`(1)/(y).(dy)/(dx)=(1)/(2).{(1)/((x-3))+(2x)/((x^(2)+4))-((6x+4))/((3x^(2)+4x+5))}`
`rArr (dy)/(dx)=((1)/(2)y).{(1)/((x-3))+(2x)/((x^(2)+4))-((6x+4))/((3x^(2)+4x+5))}`
`=(1)/(2).sqrt(((x-3)(x^(2)+4))/((3x^(3)+4x+4))).{(1)/((x-3))+(2x)/((x^(2)+4))-((6x+4))/((3x^(2)+4x+5))}`


Discussion

No Comment Found