CALCULUS
posted by Jacob on .
Use the product rule to calculate the derivative.
dh
dx
x = 4 ,
h (x) = (x^(1/2) + 7x)(9  x^1)
very weird.. i know how to do it, i used product rule and got an answer in decimal but the website is not accepting it. Can any one help me?...

Let's multiply it out and not use the product rule. The answer should be the same.
h(x) = 9x^(1/2) x^(3/2) +63x 7
dh/dx = (9/2)x^(3/2) +(3/2)x^(5/2) + 63
dh/dx @ x=4 = (9/2)(1/8) +(3/2)(1/32)+63
= 9/16 +3/64 +63