Askor said: I thought trigonometric substitution only function if there is obtainable a square root including ##sqrt x^2 + 2 ##. No. Trig substitution is helpful When you have the sum or big difference of squared phrases - they don't need to be inside a sq. root. Advertisement It can https://gabletoppak.com/hc-issues-notice-over-plea-to-make-dwarka-plastic-free/