Askor explained: I assumed trigonometric substitution only operate if there is out there a square root like ##sqrt x^2 + 2 ##. No. Trig substitution is helpful Should you have the sum or change of squared terms - they needn't be inside a sq. root. Ad It is an interesting https://gabletoppak.com/choosing-between-gable-top-packaging-and-plastic-bottles-for-your-beverage-business/