Change of Base Formula

The change of base formula rewrites a logarithm using a different, more convenient base: $\log_a b=\frac{\log_c b}{\log_c a}$. It is essential when a calculator only has base 10 or base $e$, and it also helps simplify expressions like $\log_a b\times\log_b a=1$.

You meet Change of Base Formula in the Indices, Surds and Logarithms chapter of SPM Additional Mathematics. Knowing the term precisely matters in the exam: questions often hinge on reading a keyword correctly, and because SPM marking is analytic, using the right definition in your working helps secure method marks.

Our teachers make sure a student can not only recite what Change of Base Formula means but use it fluently in a full solution.

Because the SPM Add Math paper is bilingual (BM/EN), it helps to know this term in each language: Change of Base Formula (EN) · Rumus Penukaran Asas (BM) · 换底公式 (中文)

Other key terms from the Indices, Surds and Logarithms chapter you may want to check:

• Index
• Laws of Indices
• Surd
• Rationalising the Denominator
• Logarithm
• Laws of Logarithms