Peter Math on Instagram: "Trigonometric substitution is a technique used in integral calculus to simplify difficult integrals, especially those involving square roots of expressions like a^2 - x^2, a^2 + x^2, or x^2 - a^2. By substituting a trigonometric function for the variable x, the integral is transformed into a form that is easier to work with. This method takes advantage of well-known trigonometric identities, allowing us to replace complex algebraic expressions with simpler sine, cosine,