## week 17 precalc

This week in precalc we finished our trigonometry unit with sine and cosine laws.  these are fairly simple concepts knowing that it’s just a formula and a little bit of algebra.  in Sine law you must remember that there can be two possibilities to an angle if it’s extraneous.

Sine law : $\frac {a}{sinA} = \frac {b}{sinB} = \frac {c}{sinC}$

cosine law : $a^2 = b^2+c^2-ab(cosA)$

$\frac {b^2+c^2-a^2}{2bc}$

example of sine law                                             example of cosine law