Askor said: I believed trigonometric substitution only perform if there is accessible a square root for example ##sqrt x^2 + two ##. No. Trig substitution is helpful In case you have the sum or distinction of squared terms - they don't need to be inside of a sq. root. (Athletics) https://gabletoppak.com/kerala-get-ready-to-say-no-to-plastic-from-october-2/