指數與對數(15)
Author: 藍邦偉　老師

d=2^a=12^x⇒2=12^{\frac{x}{a}}⇒2^2=(12^{\frac{x}{a}})^2⇒4=12^{\frac{2x}{a}}

$ d=3^b=12^x⇒3=12^{\frac{x}{b}} $

⇒4×3=12=12^{\frac{2x}{a}+\frac{x}{b}}

$ ⇒\frac{2x}{a}+\frac{x}{b}=1 $

$ ⇒x(\frac{2}{a}+\frac{1}{b})=1 ⇒x=\frac{1}{\frac{2b+a}{ab}}=\frac{ab}{a+2b}$

n = 1 (slider from 1 to 6, step 1)