How do you differentiate y = sqrt(x)(9 x - 8)?

1 Answer
Sep 8, 2016

(dy)/(dx)=27/2sqrtx-8/(2sqrtx)

Explanation:

Product rule states if f(x)=g(x)h(x)

then (df)/(dx)=(dg)/(dx)xxh(x)+(dh)/(dx)xxg(x)

Hence as y=sqrtx(9x-8)

(dy)/(dx)=9xxsqrtx+1/(2sqrtx)xx(9x-8)

= 9sqrtx+(9x)/(2sqrtx)-8/(2sqrtx)

= 9sqrtx+9/2sqrtx-8/(2sqrtx)

= 27/2sqrtx-8/(2sqrtx)