Askor claimed: I thought trigonometric substitution only work if there is out there a sq. root including ##sqrt x^two + 2 ##. No. Trig substitution is helpful For those who have the sum or big difference of squared phrases - they needn't be inside a square root. Customization: Understanding that https://gabletoppak.com/bioplastics-greenwashing-or-genuine-solution-the-truth-behind-the-hype/