Askor explained: I assumed trigonometric substitution only operate if there is obtainable a sq. root for example ##sqrt x^2 + 2 ##. No. Trig substitution is useful When you've got the sum or distinction of squared terms - they need not be inside a sq. root. To limit the activity https://gabletoppak.com/sustainability-in-action-gable-top-cartons-to-save-our-oceans/