Steffensen's Method is a type of meta - iterative method leveraging [[Aitken's Delta Squared]] to 'boost' a [[Linear Convergence|linearly convergent]] method (ex. [[Fixed Point Method]]) . With our method $M$, iterate $3$ times. Use these three values with [[Aitken's Delta Squared]] to get the next iteration. Iterate $M$ two more times, and then use the past three with [[Aitken's Delta Squared]] and so on. $ \begin{align} M(x_{n}) &\to M(x_{n+1}) \\ &\to M(x_{n+2}) \\ &\to A_{\Delta^{2}}\pa{ M(x_{n}) \to M(x_{n+1}) \to M(x_{n+2}) }\\ &\to M(\cdots) \\ &\to \cdots \end{align} $ The [[Numerical Analysis Error Bounds|Error Bound]] / [[Order of Convergence]] of this method is dependent on the specific method. $\huge $