[latex]log_ax=2 o a^2=x\\log_bx=3 o b^3=x\\log_cx=6 o c^6=x\\a^2=b^3=c^6 o b=a^frac{2}{3} wedge c=a^frac{2}{6}=a^frac{1}{3}\\log_{abc}x=y o(abc)^y=x o(aa^frac{2}{3}a^frac{1}{3})^y=x o(a^{1+frac{2}{3}+frac{1}{3}})^y=a\\ o(a^2)^y=x o a^{2y}=x o a^{2y}=a^2iff2y=2 o y=1[/latex] [latex]Zalozenia:\ x; a; b; cinmathbb{R^+} wedge a eq1 wedge b eq1 wedge c eq1 wedge abc eq1.[/latex]
[latex]zalozenia do zadania: a,b,c>0 i a,b,c eq 1\\na podstawie twierdzenia o zamianie podstawy logarytmu mamy:\\ log_ax=2 Leftrightarrow log_xa= frac{1}{2}\\log_bx=3 Leftrightarrow log_xb= frac{1}{3}\\log_cx=6 Leftrightarrow log_xc= frac{1}{6}\ \[/latex] [latex]wobec tego:\ \log_x(abc)=log_xa+log_xb+log_xc= frac{1}{2}+ frac{1}{3}+ frac{1}{6}= frac{3}{6}+ frac{2}{6}+ frac{1}{6}= frac{6}{6}=1\ \log_{abc}x= frac{1}{log_x(abc)} =1 dla abc eq 1[/latex]