Question

Considerando log2=0,301,log3=0,477,log5=0,7,log7=0,845 calcule:
a)log 30
b)log 20
c)log raiz quadrada de 7
d)log 5/3

Answer 1

a) $\log30=\log(2.3.5)=\log 2+\log 3+\log 5=0,301+0,477+0,7=1,478$

b) $\log20=\log(2^2.5)=\log2^2+\log5=2\log2+\log5=2(0,301)+0,7=1,302$

c) $\log\sqrt{7}=\log7^{1/2}=\frac{1}{2}.\log7=\frac{\log7}{2}=\frac{0,845}{2}=0,4225$

d) $\log\frac{5}{3}=\log5-\log3=0,7-0,477=0,223$