3) Integration by substitution

•  Integration by substitution involves substituting a new variable for the variable of integration.
• This is useful when the integrand contains a function that can be simplified by substitution.
• The technique involves choosing a new variable, computing its derivative, and substituting into the integral.
• The resulting integral is often simpler to solve.

Important Formulas to Remember in these topic

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$$\int f(g(x))g'(x)dx = \int f(u)du$$

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