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• cos(π/4) = √(2)/2 You are correct that it is 1 /√(2) but it is also √(2)/2. And that's because 1 / √(2) = √(2)/2 1 / √(2) Rationalize the denominator of this and you get: √(2) / 2 Hope it helps

  in how is cos(π/4) = (√2)/2 ? Comment by markus0003000 June 2021