Formula transposition

Basic Formula Transposition

  • Purpose: To calculate any value of a formula by making that value the 'subject'.

  • Subject Definition: The value calculated alone on one side of the '=' sign.

  • Example:

    • Original Formula: V = IR

    • To calculate 'R':

      • Transpose: R = V/I

      • Rearrangement: I = V/R

  • Key Rules: Follow rules to transpose and balance the formula.

How to Transpose Formulae

  • Method: Apply opposite functions to remove parts of the formula.

  • Steps:

    • Identify the desired subject of the formula.

    • Apply opposite operations:

      + removes -

      - removes +

      × removes ÷

      ÷ removes ×

      √ removes 2 or power

      Sin removes Sin-1 and vice versa.

  • Balance Equation: Apply the same operation to both sides of the '='.

  • Chunk Removal: Can move multiple elements at once (e.g., D = Vl/(P x I x F)).

Basic Formula Transposition Examples

  • Example 1: V = IR

    • Rearranging for R:

      • R = V/I

  • Example 2: S = √(I² × t)

    • Rearranging for t:

      • Steps:

        1. Square both sides: (S²) = I² × t

        2. Divide I² to isolate t: t = (S²)/(I²)

Summary of Formula Transposition

  • Steps to Follow:

    • Identify the subject to isolate.

    • Apply opposite functions to cancel terms.

    • Ensure to apply the same function to both sides of the equation.

  • Operations Recap:

      • to remove -

      • to remove +

    • × to remove ÷

    • ÷ to remove ×

    • 2 to remove √

    • Sin-1 to remove Sin and vice versa.