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Brainlag Learn / GCSE Maths

Surds

Exact answers with square roots: simplifying, multiplying and expanding, rationalising denominators, and surds in Pythagoras and quadratics. Higher tier.

Lessons

  1. Simplifying surdsWhat a surd is, taking square factors out of a root, and adding and subtracting like surds. 20 min, with the Scientific Calculator, free, Higher tier
  2. Multiplying and expanding surdsMultiply and divide surds, square them, and expand brackets that contain surds. 25 min, with the Scientific Calculator, free, Higher tier
  3. Rationalising the denominatorRemove a surd from the bottom of a fraction, with √k or a bracket like (b + √k) underneath. 25 min, Plus, Higher tier
  4. Exact answers with surdsUse surds for exact lengths, areas and distances, and for quadratic solutions in the form a ± b√c. 25 min, with the Equation Solver, Plus, Higher tier

Practise and test

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