Askor said: I thought trigonometric substitution only do the job if there is accessible a sq. root for example ##sqrt x^2 + two ##. No. Trig substitution is helpful When you've got the sum or variation of squared conditions - they needn't be within a sq. root. Front Gable: A https://gabletoppak.com/water-in-a-sustainable-box-the-future-of-eco-friendly-hydration/