Maryy asdokvnoerinakjdlaksdf k?

This friday, we did some learning, and i'm gonna show you.

Section 10.1

This whole section is about finding the sin and cos of certain angles that aren't already on the trig chart. and oh, no calculators

Here's your formulas :

Cos( alpha +/- beta) = cosalphacosbeta-/+sinalphasinbeta
Sin(alpha+/- beta) = sinalphacosbeta+/-cosalphacosbeta
(-note the plus and minuses*)

Example!
sin 15
ok, the process is that you find two numbers on the trig chart that add or subtract to get the number, and use them as alpha and beta. in this case, you can use two different combinations but we'll go with 45 and 30 so alpha =45 and beta =30
plug in your formula which you know is the sin version because of the trig function.
you get sin(45-30) =sin45cos30-cos45sin30
you take the values from the trig chart and subtract and you get
square root of 6 - square root of 2 over 4.
this section is really simple, i'm hoping it stays simple.