Askor claimed: I believed trigonometric substitution only do the job if there is offered a sq. root for instance ##sqrt x^2 + two ##. No. Trig substitution is helpful For those who have the sum or distinction of squared terms - they needn't be inside a sq. root. Entrance Gable: https://gabletoppak.com/free-water-advertising-a-sustainable-and-emotional-path-to-powerful-brand-recognition/