For some [[Continuous Function|Continuous Function]] $f\in\mathcal C[a,b]$, the secant method is a type of iterative method to find the [[Roots|root]] of $f$. $\huge x_{n+1} = \frac{ x_{n-1}f(x_{n}) - x_{n}f(x_{n-1}) }{f(x_{n})-f(x_{n-1})} $