Question

Sendo a função f: R* → R tal que f(x)=x elevado a 3 - 4 / x calcule.

c) f(-2)
b) f(2)
d) f (3)
a) f(1)
e) f (1/2)​

Answer 1

Resposta:

$f(x) = x^{3} - \frac{4}{x}$

$a) f(1) = 1^{3} - \frac{4}{1} = -3$

$b) f(2) = 2^{3} - \frac{4}{2} = 8 - 2 = 6$

$c) f(-2) = -2^{3} - \frac{4}{-2} = -8 + 2 = -6$

$d) f(3) = 3^{3} - \frac{4}{3} = 27 - 4/3 = 77/3$

$e) f(1/2) =\frac{1}{2} ^{3} - \frac{4}{1/2} = \frac{1}{8} - 8 = \frac{-63}{8}$