Askor claimed: I thought trigonometric substitution only do the job if there is obtainable a sq. root including ##sqrt x^2 + 2 ##. No. Trig substitution is useful if you have the sum or distinction of squared phrases - they don't need to be inside of a sq. root. Gabletop https://gabletoppak.com/lakes-developed-under-smart-cities-initiative-in-coimbatore-turn-dumping-grounds-for-plastic-waste/