Askor reported: I assumed trigonometric substitution only get the job done if there is on the market a sq. root like ##sqrt x^two + two ##. No. Trig substitution is helpful When you have the sum or distinction of squared phrases - they needn't be inside a square root. Advertisement https://gabletoppak.com/aseptic-tetra-pak-vs-non-aseptic-gable-top-choosing-the-right-carton-for-your-needs/