Askor explained: I assumed trigonometric substitution only operate if there is out there a square root for example ##sqrt x^two + 2 ##. No. Trig substitution is useful When you have the sum or variation of squared phrases - they need not be within a sq. root. The exponential dies https://gabletoppak.com/the-growing-threat-of-marine-pollution-and-how-gabletop-cartons-offer-a-solution/