Question

sabendo que log 2= 0,301 e log 3= 0,477 e log 5= 0,700. Calcule os seguintes logaritimos
A- log 10
B- log 9
C- log 15
D- Log 7,3

Answer 1

a) log 10 = log 2*5 = log 2 + log 5 = 0,3 + 0,7 = 1

b) log 9 = log 3*3 = log 3 + log 3 = 0,477 + 0,477 = 0,954

c) log 5 = log 5*3 = log 5 + log 3 = 0,700 + 0,477 = 1,177

d) log 7,5 = log 5*5*3/10 = log5 + log 5+ log 3 - log 10 = 0,7 + 0,7 + 0,477 - 1 = 0,877

Answer 2

a) $log10 = log5*2 = log5 + log2 = 0,7+0,301 = 1,01$

b) $log9 = log3^3 = 3*log3 = 3*0,477 = 1,431$

c) $log15 = log5*3 = log5 + log3 = 0,7 + 0,477 = 1,177$

d) 

$log7,5 = log\dfrac{75}{10} = log75 - log10 = log3*5^2 - log 10 \\ \\ log3+log5^2-log10 = log3+2*log5-log10 \\ \\ 0,477+2*0,7-1 = 0,477+1,4-1 = 0,877$