Askor mentioned: I thought trigonometric substitution only do the job if there is out there a sq. root like ##sqrt x^two + 2 ##. No. Trig substitution is useful When you've got the sum or variance of squared phrases - they needn't be within a sq. root. Simple to operate, https://gabletoppak.com/customized-packaged-drinking-water-with-your-brand-logo/