Geometric Mean, Trig, Vectors, Other Such Torture...

this is a test where having lots of colors would be useful, because otherwise everything looks confusing.
leg of right triangle is geom mean
btwn piece of hypot next to it and length of full hypot
altitude is geom mean
btwn the 2 pieces of the hypot
trig functions
SOH CAH TOA. that is all.
law of sines
If you know an angle and the measure of opp side:
sinA/a = sinB/b = sinC/c
law of cosines
if you have info about all 3 sides or side angle side:
a^2 = b^2 + c^2 - 2bc(CosA)
basically, a directed line segment
written like <x,y> (btw this is called component form)
length of a vector
usually you can use pythagorean theorum to find this.
the angle that the vector makes with a horizontal line. measured clockwise from x axis. usually involves N,S,E,W because Draz likes word problems a lot.
equal vectors
have same magnitude and direction
parallel vectors
have the same or opposite direction
resultant vector
the sum of 2 vectors. you just add them.
direction of resultant vector