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Real Linear Equation Solutions
Real Square Roots
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Real Equation Solutions

Why

Given a real valued function (e.g., a polynomial) how do we compute its roots?

Definition

Given $f: \R \to \R $, we call $f(x) = 0$ a nonlinear equation (a nonlinear homogenous equation). If $x \in \R $ with $f(x) = 0$ we call $x$ a root or solution of $f$.

Examples

For a classic example, suppose $s \in \R $ is given and consider the function $f: \R \to \R $ defined by

\[ f(t) = t - \sqrt{s} \]

Then the solutions $r \in \R $ for which $f(r) = 0$ are those points for which

\[ 0 = r - \sqrt{s} \Rightarrow r = \sqrt{s} \]

In other words, the roots of $s$.

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