Exponential Equations (Edexcel AS Maths): Revision Note

Exponential equations

What are exponential equations?

• An equation where the unknown is a power

• In simple cases the solutions can be “spotted”

  

How do I solve exponential equations?

• Laws of Indices are often needed to rewrite equations

• Laws of Logarithms are used to solve exponential equations

• ln (log_e) is often used

• Answers are often written in terms of ln

How do I solve hidden quadratic exponential equations?

•  Look out for “hidden” squared terms, these are hidden quadratics which will need to be solved

  • 4^x = (2²)^x = 2^2x = (2^x)²

  • e^2x = (e²)^x = (e^x)²