Question

if f(x)=(2^(1/2))(x^3-6x^(1/2)+7), find f'(9)

Answer 1

first get its derivative,, recall some techniques on how to derive~
the derivative of this function is:
f'(x) = [sqrt(2)]*{3x^2 - [3/(sqrt(x))}

substituting the value of x (which is 9):
f'(9) = [sqrt(2)]*{3(9)^2 - [3/(sqrt(9))}
f'(9) = [sqrt(2)]*(243 - 1)
f'(9) = 242*sqrt(2)

so there,, :)