Askor said: I believed trigonometric substitution only function if there is offered a square root for instance ##sqrt x^2 + two ##. No. Trig substitution is useful In case you have the sum or big difference of squared terms - they don't need to be inside of a square root. https://gabletoppak.com/single-use-plastic-water-bottles-will-not-be-available-in-himachal-from-june-1-use-glass-bottles-and-dispensers-instead/