calculus
posted by lisa .
Use a linear approximation of f(x)=^3√x at x=8 to approximate ^3√7.
Express your answer as an exact fraction.

what are you using this symbol ^ for?

its cubed

do you meant the f(x)=cubrtx ?
then f'= 1/ 3(cubrtx)^2
f(7)=f(8)f'(1)=cubrt81/3(cubrt1)2
= 21/3=1 2/3=5/3