…is a series for which pairs cancel out:

\begin{equation} (1-x)(1+x+ \dots + x^{n-1}) \end{equation}

you will note that, though the expansion of this result, pairs of:

\begin{equation} -x^{j} + x^{j} \end{equation}

form. And you will note those cancel. Hence this is a telescoping series.

A Term-Document Matrix is a boolean matrix of: rows—“terms”, the search keywords—and columns—“documents”, which is the document. Each element \((x,y)\) is \(1\) if \(y\) contains term \(x\), and \(0\) otherwise.

To perform a search, we take a boolean operation over each row (usually either complement for NOT or identity), and AND it with all other terms. The resulting boolean string are the valid documents.

Notably, this is quite intractable because the matrix is quite (words times documents) blows up. However, this representation is QUITE SPARSE. So, ideally we only store it sparsely.

Given what you claim as a normal distribution, we can test for its normality. Any distribution you claim as normal has to follow that:

\begin{equation} np \geq 10 & n(1-p) \geq 10 \end{equation}

that number of successes and failures need both be greater than or equal to ten.

How many bugs are in 1,000 lines of code?

• Typical code: 1-10
• Platform code: 0.1-1
• The best—NASA: 0.01-0.1

Never assume your software doesn’t have bugs.

Test-Driven Development

Test before you build!

• Specs are already written
• We know what the expected behavior is
• We can write tests for the expected behavior first
• All tests fail to start
• We know we are done writing code when all tests pass

“NYI” (not-yet implemented)