Askor claimed: I assumed trigonometric substitution only do the job if there is offered a sq. root like ##sqrt x^2 + two ##. No. Trig substitution is useful For those who have the sum or change of squared terms - they need not be inside of a sq. root. , https://gabletoppak.com/hc-issues-notice-over-plea-to-make-dwarka-plastic-free/