Determine the Extrema

Question

Determine the extrema for f(x) = (√x)/x+10

Answer 1

f(x) = sqrt(x)/x + 10 = x^(1/2)/x + 10 = x^(-1/2) + 10

f'(x) = (-1/2) x ^(-3/2)

0 = (-1/2) x^(-3/2)

0 = x^(-3/2) <-- multiplies by -2

0 = 1 <--- multiplies by x^(3/2)

there are no extrema