Daily Archives: May 20, 2017

This week in math 10 we learned about multiplying polynomials, distributive property, and the acronym FOIL.

The acronym FOIL stands for First terms, Outside terms, Inside terms, and Last terms. This is in regards to which terms you multiply and in what order, before you combine like terms.

Distributive property (FOIL) with binomials would look like: (a+b) (c+d) = ac + ad + bc + bd.

Example: In this expression, you begin by multiplying 3x and 2x, the FIRST terms, then 3x and 5, the OUTISDE terms, then 2 and 2x, the INSIDE terms, and finally 2 and 5, the LAST terms.

This week in math we learned how to calculate unknown angles of triangles given the sine, cosine and tangent ratios. The easiest way to remember these is the acronym SOH CAH TOA. The first letter stands for the ratio, and the second and third letters represents what lengths you put into the expression. When the expression is written, the second letter is in the numerator, and the third goes in the denominator.

To use the ratios you have to have your triangle labelled correctly. Then you can use the opposite, adjacent, and hypotenuse lengths to find your angle. These are the lengths represented by O, A, and H in SOH CAH TOA.

Example: In the triangle (see below) angle x is our unknown angle. Because we have at least 2 side lengths, we can find it. In this case the opposite and adjacent lengths will be used, so the tangent ratio will be the one we use. Then you simply set up the equation: (5/6), and plug it into your calculator. This gives us roughly 39.8° which will be rounded to 40°.