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๐Ÿ“˜Intermediate Algebra Unit 8 Review

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8.6 Solve Radical Equations

๐Ÿ“˜Intermediate Algebra
Unit 8 Review

8.6 Solve Radical Equations

Written by the Fiveable Content Team โ€ข Last updated September 2025
Written by the Fiveable Content Team โ€ข Last updated September 2025
๐Ÿ“˜Intermediate Algebra
Unit & Topic Study Guides

Radical equations are a crucial part of algebra, involving expressions with roots. These equations require special techniques to solve, including isolating radicals and raising both sides to a power to eliminate the root.

Solving radical equations involves careful steps to avoid extraneous solutions. Applications of these equations are found in real-world problems, making them important for practical problem-solving in fields like physics and engineering.

Solving Radical Equations

Equations with single radicals

  • Isolate radical expression on one side of equation
    • Perform same operation on both sides to maintain equality (addition, subtraction, multiplication, division)
  • Raise both sides of equation to power of index of radical
    • Square both sides for square roots
    • Cube both sides for cube roots
    • Eliminates the radical
  • Solve resulting equation
    • Combine like terms (variables, constants)
    • Isolate variable using inverse operations (inverse functions)
  • Check solution by substituting back into original equation
    • Reject extraneous solutions that don't satisfy original equation (introduced by squaring or cubing)

Equations with multiple radicals

  • Isolate one radical expression on one side of equation
    • Perform same operation on both sides to maintain equality (addition, subtraction, multiplication, division)
  • Raise both sides of equation to power of index of isolated radical
    • Eliminates one radical expression
  • Repeat process of isolating and eliminating radicals until single radical remains
    • Isolate remaining radical
    • Raise both sides to power of index of radical
    • Solve resulting equation
  • Check solution by substituting back into original equation
    • Reject extraneous solutions that don't satisfy original equation (introduced by repeated squaring or cubing)

Applications of radical equations

  • Identify unknown quantity and assign variable
  • Translate problem into radical equation using given information
    • Express relationships between quantities using mathematical symbols ($+, -, \times, \div, =$)
  • Solve radical equation following appropriate steps
    • Isolate radical(s)
    • Eliminate radical(s) by raising both sides to appropriate power
    • Solve resulting equation
  • Interpret solution in context of problem
    • Determine if solution makes sense given real-world context (positive lengths, times)
    • Reject extraneous solutions that don't apply to problem (negative values when not applicable)
  • Express final answer in appropriate units and format
    • Round answer if necessary based on context of problem (to nearest whole number, tenth, etc.)

Solution Analysis

  • Determine the nature of solutions:
    • Real solutions: values that satisfy the equation and exist on the real number line
    • Imaginary solutions: complex numbers involving the square root of negative numbers
  • Verify solutions through algebraic manipulation of the original equation
  • Consider the domain of the equation, including any restrictions due to radicals or absolute value expressions