Askor mentioned: I thought trigonometric substitution only do the job if there is out there a sq. root including ##sqrt x^two + two ##. No. Trig substitution is helpful if you have the sum or change of squared phrases - they don't need to be inside a square root. The https://gabletoppak.com/what-makes-gabletop-pak-cartons-a-better-choice-than-plastic-bottles/