Askor claimed: I thought trigonometric substitution only perform if there is out there a sq. root which include ##sqrt x^two + 2 ##. No. Trig substitution is useful if you have the sum or distinction of squared terms - they don't need to be inside a square root. Front Gable: https://gabletoppak.com/how-white-label-water-bottles-can-skyrocket-your-business/