A4. Which of the following equations is not true?
(A) $\log _{4} 2=2$
(B) $\log _{3} \sqrt{3}=\frac{1}{2}$
(C) $\log _{10} 0.1=-1$
(D) $\log _{7} 7=1$
(E) $\log _{5} 1=0$
A4. The first inequality is incorrect, since $\log _{4} 2=\frac{1}{2}$, because $4^{\frac{1}{2}}=2$.