Ch 1 · Ratio, Proportion, Indices and Logarithms

5 concept points · 5 formulas · 4 exam-critical points.

📘 Core concepts

• 1Ratio: comparison of two quantities of same kind in simplest form.
• 2Proportion: equality of two ratios; a:b = c:d ⇒ ad = bc.
• 3Indices laws: aᵐ · aⁿ = aᵐ⁺ⁿ, aᵐ/aⁿ = aᵐ⁻ⁿ, (aᵐ)ⁿ = aᵐⁿ.
• 4Logarithms: if aˣ = N then log_a N = x.
• 5Common log (base 10), natural log (base e).