Askor claimed: I assumed trigonometric substitution only do the job if there is accessible a square root such as ##sqrt x^two + two ##. No. Trig substitution is useful In case you have the sum or difference of squared conditions - they don't need to be inside a sq. root. https://gabletoppak.com/why-gabletop-cartons-outshine-pet-bottles-for-branding-opportunities/