Askor reported: I thought trigonometric substitution only get the job done if there is obtainable a sq. root like ##sqrt x^2 + two ##. No. Trig substitution is useful In case you have the sum or change of squared terms - they need not be inside of a sq. root. https://gabletoppak.com/how-gabletop-cartons-are-helping-water-brands-combat-climate-change/