Question

Se f(x)=㏒$\frac{ x^{2} }{x+11}$, o valor de f(-1) é:
(A) -2
(B) -1
(C) 0
(D) 1
(E) 2

Answer 1

Estou naturalmente  considerando que a base do log seja 10
$f(-1) = log \frac{(-1)^2}{-1+11} = log \frac{1}{10} = log 1 - log 10 = 0 - 1 = -1$

Answer 2

f(-1)=㏒$\frac{-1^{2} }{1-11}$

f(-1)=㏒$\frac{1}{10}$
f(-1)=㏒ 0.1
log 0.1=-1