# The Apple Method

## What is the Apple Method?

The Apple Method is a method for solving algebra problems. An apple is used to make a clever algebraic substitution.

## Why Apple?

A few reasons:

1. When you use the Apple Method, you can box what you are substituting with the apple. When you use $x$ as a substitution, instead of actually boxing it, you are just crossing it out.

2. Apples are easier to draw.

3. Apples are good for you.

4. An Apple a Day Keeps the Doctor Away.

## LaTeX code for apple

$(^{^(})$, or if you want some color, $\textcolor{red}{(\textcolor{green}{^{^(}})}$

## Examples

1. Evaluate: $$\sqrt{6+\sqrt{6+\sqrt{6+\cdots}}}$$

$\emph{Solution:}$

If we set $\textcolor{red}{(\textcolor{green}{^{^(}})}=\sqrt{6+\sqrt{6+\sqrt{6+\cdots}}}$, we can see that $\textcolor{red}{(\textcolor{green}{^{^(}})}^2= 6+\textcolor{red}{(\textcolor{green}{^{^(}})}$.

Solving, we get $\textcolor{red}{(\textcolor{green}{^{^(}})}=\boxed{3}$

2. If $$\sqrt{x\cdot\sqrt{x\cdot\sqrt{x\cdots}}} = 5$$

Find x.

$\emph{Solution:}$

If we set $\sqrt{x\cdot\sqrt{x\cdot\sqrt{x\cdots}}}$ equal to $\textcolor{red}{(\textcolor{green}{^{^(}})},$ we get $\textcolor{red}{(\textcolor{green}{^{^(}})} = 5$ and $\textcolor{red}{(\textcolor{green}{^{^(}})}^2 = x \cdot \textcolor{red}{(\textcolor{green}{^{^(}})} = 25.$

Simplifying, we find $\textcolor{red}{(\textcolor{green}{^{^(}})} = x,$ so $x = \boxed{5}$

3. Evaluate: $$\frac{\frac{1}{1^2}+\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+\ldots}{\frac{1}{1^2}+\frac{1}{3^2}+\frac{1}{5^2}+\frac{1}{7^2}+\ldots}$$

$\emph{Solution:}$

Let $\textcolor{red}{(\textcolor{green}{^{^(}})}=\frac{1}{1^2}+\frac{1}{2^2}+\frac{1}{3^2}+\cdots$. Note that $\frac{1}{1^2}+\frac{1}{3^2}+\frac{1}{5^2}+\cdots = \left( \frac{1}{1^2}+\frac{1}{2^2}+\frac{1}{3^2}+\cdots \right) - \left( \frac{1}{2^2}+\frac{1}{4^2}+\frac{1}{6^2}+\cdots \right) = \textcolor{red}{(\textcolor{green}{^{^(}})} - \frac{1}{2^2}\cdot\textcolor{red}{(\textcolor{green}{^{^(}})} = \frac{3}{4}\cdot\textcolor{red}{(\textcolor{green}{^{^(}})}.$

Thus, the answer is $\frac{\textcolor{red}{(\textcolor{green}{^{^(}})}}{\frac34\cdot\textcolor{red}{(\textcolor{green}{^{^(}})}}=\boxed{\frac34}.$

## Extensions

### The :) Method

When more than one variable is needed, pears, bananas, stars, and smiley faces are usually used.