Askor reported: I believed trigonometric substitution only do the job if there is available a sq. root like ##sqrt x^two + 2 ##. No. Trig substitution is helpful if you have the sum or variance of squared terms - they needn't be within a sq. root. The exponential dies off https://gabletoppak.com/the-benefits-of-switching-to-sustainable-milk-cartons-today/