SL 1.8 SOLVING EQUATIONS USING TECHNOLOGY

Equation Type What You Must Be Able To Do
Systems of Linear Equations Solve up to 3 variables using technology
Polynomial Equations Find accurate roots (zeros) using GDC

πŸ“Œ Systems of Linear Equations (Using Technology)

A system of linear equations is a group of two or more equations that must be satisfied at the same time.
Each solution gives values that work in every equation simultaneously.

  • Equations can have 2 or 3 variables.
  • The solution is where all equations intersect.
  • In exams, there will always be a unique solution.

Example idea:

  • 2x + y = 7
  • x βˆ’ y = 1
  • Technology quickly finds x = 2 and y = 3
🌍 Real-World Connection
Electrical circuit problems (Kirchhoff’s Laws in physics) rely on solving systems of equations to determine currents and voltages.

πŸ“Œ Polynomial Equations & Roots

A polynomial equation is an equation of the form:

axⁿ + bxⁿ⁻¹ + … + c = 0

The solutions are called the roots or zeros of the function. These are the x-values where the graph crosses the x-axis.

  • Quadratic β†’ up to 2 roots
  • Cubic β†’ up to 3 roots
  • Higher powers β†’ more roots

Manual solving is not required β€” technology is always used.

πŸ“— GDC Tip
Use Graph β†’ Zero or Poly-Root to find solutions directly.
Always verify roots by substituting them back into the equation.

πŸ“Œ Interpretation of Solutions

Solutions must always be interpreted in the context of the problem:

  • Time cannot be negative
  • Distance cannot be imaginary
  • Population cannot be fractional in certain models
πŸ” TOK Perspective
Mathematics uses words like real and imaginary differently from everyday language β€” how does language shape how we interpret knowledge?

πŸ“Œ Exam Expectations

  • No specific algebraic solving method is required
  • You must correctly interpret the technology output
  • Answers should always be checked for context validity
🧠 Examiner Tip
Most errors occur when students accept a root without checking if it makes real-life sense.
πŸ“ IA Spotlight
You can model real systems using polynomial or simultaneous equations:

  • Motion problems
  • Break-even analysis
  • Population models
πŸ“ Paper 1 Strategy
Always:

  • Write down what the variables represent
  • Confirm the number of expected solutions
  • Round only at the final stage

πŸ“Œ Why This Topic Matters

  • Used in physics, economics, engineering, AI models
  • Allows prediction and optimization
  • Forms the basis of most modelling methods