Askor claimed: I thought trigonometric substitution only get the job done if there is out there a square root including ##sqrt x^two + 2 ##. No. Trig substitution is helpful For those who have the sum or change of squared terms - they don't need to be inside a square https://gabletoppak.com/bioplastics-greenwashing-or-genuine-solution-the-truth-behind-the-hype/