Question

considere a operação fracionária f (x, y, z) = x^2y^-1/3sqrtz. o seu valor numérico quando x=4, y=-2 e z=-8 é?

Answer 1

$f(x,y,z)=\dfrac{x^2y^{-1}}{3\sqrt{z}}\\\\\\f(4,-2,-8)=\dfrac{(4)^2(-2)^{-1}}{3\sqrt{-8}}\\\\\\f(4,-2,-8)=\dfrac{-8}{3\cdot2i\sqrt{2}}\\\\\\f(4,-2,-8)=-\dfrac{4}{3i\sqrt{2}}\\\\\\f(4,-2,-8)=-\dfrac{4}{3i\sqrt2}\cdot\dfrac{i\sqrt2}{i\sqrt2}\\\\\\f(4,-2,-8)=-\dfrac{4i\sqrt2}{-6}\\\\\\\boxed{\boxed{f(4,-2,-8)=\dfrac{2i\sqrt2}{3}}}$