Askor explained: I believed trigonometric substitution only get the job done if there is out there a sq. root for instance ##sqrt x^2 + 2 ##. No. Trig substitution is useful When you've got the sum or change of squared conditions - they need not be inside a sq. root. https://gabletoppak.com/how-white-label-water-bottles-can-skyrocket-your-business/