Askor said: I thought trigonometric substitution only function if there is obtainable a square root for instance ##sqrt x^2 + 2 ##. No. Trig substitution is helpful When you have the sum or variance of squared phrases - they don't need to be inside a sq. root. Convenient to use, https://gabletoppak.com/elevate-your-brand-with-gable-top-paks-white-label-water-packaging/