Answer:
√56/8
Step-by-step explanation:
Let the number be x
f(x) = 8x + 7(1/x)
f(x) = 8x + 7/x
Differentiate f(x) with respect to x
f'(x) = 8x - 7/x = 0
8 - 7/x^2 = 0
(8x^2 - 7)/2 = 0
8x^2 - 7 = 0
8x^2 = 7
x^2 = 7/8
x = √7/8
x = √7 /√8
x = (√7/√8)(√8/√8)
x = (√7*√8) / √8*√8)
x = √56/8
