Direct/Indirect Proportion

• What is the definition of direct proportion?

  As one variable increases, the other increases at the same rate.
• What is the definition of inverse proportion?

  As one variable increases, the other decreases proportionally.
• What is the equation for direct proportion?

  y = kx
• What is the equation for inverse proportion?

  y = k/x
• What type of graph represents direct proportion?

  A straight line through the origin.
• What type of graph represents inverse proportion?

  A hyperbola.
• What happens to y if x doubles in a direct proportion?

  If x doubles, y doubles.
• What happens to y if x doubles in an inverse proportion?

  If x doubles, y halves.
• What is constant in direct proportion?

  The ratio (y/x) is constant.
• What is constant in inverse proportion?

  The product (xy) is constant.
• What are the key differences between direct and inverse proportion?

  • Direct Proportion:
  • Equation: y = kx
  • Graph: Straight line
  • As x increases, y increases
  • Constant: Ratio (y/x)

  
  

  • Inverse Proportion:
  • Equation: y = k/x
  • Graph: Hyperbola
  • As x increases, y decreases
  • Constant: Product (xy)