>>294
log 11 = 1.04139268515822504075019997124302…
log 3 = 0.477121254719662437295027903255115…
対数表か電卓を使う
log x =ln x /ln 10
ln(x+1)=x - x^2/2 + x^3/3 - x^4/4 + x^5/5 - x^6/6 + …