diff --git a/complete-the-square.tex b/complete-the-square.tex index d54ffe1..5b3dee2 100644 --- a/complete-the-square.tex +++ b/complete-the-square.tex @@ -7,6 +7,8 @@ \usepackage{float} \raggedbottom +\usepackage{enumitem} + % Where are our images? \graphicspath{{images/}} @@ -63,9 +65,20 @@ It also provides several worked equations to serve as examples. \section{Quadratic Equations} -\textbf{Quadratic equations} are equations of the form $ax^2+bx+c=0$. +\textbf{Quadratic equations} are equations of the form $ax^2+bx+c=0$, or that can be written in that form. -The simplest quadratic equation to solve is the type where both sides are a perfect square, because you can solve them by taking the square root of both sides: +When we say ``of the form'' what we mean is + +\begin{itemize}[noitemsep] + \item The letters $a, ~b,$ and $c$ represent constants, and that both $b$ and $c$ can be zero. + \item There is one term that contains the variable $x^2$ +\end{itemize} + +For example, the equation $3x^2+2x=5$ is a quadratic equation because it is written in the form $ax^2+bx+c=0$. + +However, the equation $5=2-3x^2$ is also a quadratic equation because it can be rewritten as $3x^2+3=0$. In this case, the value for $b$ is zero. (This could also be written as $3x^2+0x+3=0$.) + +\paragraph{Perfect Square Quadratic Equations} The simplest quadratic equation to solve is the type where both sides are a perfect square, because you can solve them by taking the square root of both sides: \begin{align}\label{eq1} \begin{split} @@ -80,7 +93,7 @@ x &= \pm3 \paragraph{Note:} Because we are taking the square root of a constant, we must include both the positive and negative values of the square root as the solution, hence $\pm3$. Substituting either $3$ or $-3$ into $x$ in the original equation results in a value of 36. (In story problems, the situation may mean that we can safely ignore one of these values.) -\paragraph{Factorable equations} The other type of quadratic equation is one that can easily be solved by factoring. For example, +\paragraph{Factorable Quadratic Equations} The other type of quadratic equation is one that can easily be solved by factoring. For example, \begin{align}\label{eq2} \begin{split} @@ -156,7 +169,7 @@ and then solve for $x$ (step six): \[x=\pm\sqrt{3} -2\] Conventionally, we would write this as $x=-2+\sqrt{3}, -2-\sqrt{3}$. -\krule{6pt}{6pt} +\newpage \noindent{}Here is the entire sequence all together: @@ -176,18 +189,27 @@ x &= -2\pm\sqrt{3} && && &&\text{Step 6} \hrule -\section{Example \#2} +\subsection{Example \#2} For our second example, we will look at an equation where $a$ is not equal to 1. -\section{Example \#3} +\subsection{Example \#3} For our third example, we will look at an equation where the right side is not a perfect square. -\section{Example \#4} +\subsection{Example \#4} For our fourth example, we will look at an equation where neither $a$ is equal to 1 nor the right side is a perfect square. -\pagestyle{lastpage}% Remove the header from the last page; comment this out if the document ends on an odd-numbered page +\section{More Worked Examples} + +\subsection{Example \#5.1} + +\subsection{Example \#5.2} + +\section{An Explanation of the Quadratic Equation} + +%\pagestyle{lastpage} +% Remove the header from the last page; comment this out if the document ends on an odd-numbered page \end{document} \ No newline at end of file