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Remainder Theorem

Question

Find the remainder when \(x^2 - 2x - 3\) is divided by \(x + 1\) using the Remainder Theorem

Solution

Show solution Hide solution Fully worked — 4 steps
  1. Set up the function and the value to substitute

    Let \(f(x) = x^2 - 2x - 3\). The divisor is \(x + 1\), so we evaluate at \(x = -1\). By the Remainder Theorem, the value of \(f(-1)\) is the remainder.

    \[ f(x) = x^2 - 2x - 3 \]
  2. Substitute \(x = -1\) into \(f(x)\)
    \[ f(-1) = (-1)^2 - 2(-1) - 3 \]
  3. Solve for \(f(-1)\)
    \[ f(-1) = 1 + 2 - 3 = 0 \]
  4. Final answer

    That is, the remainder is 0.

    \[ f(-1) = 0 \]