12 terms

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

this is a test where having lots of colors would be useful, because otherwise everything looks confusing.
###### PLAY
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)
vector
basically, a directed line segment
written like <x,y> (btw this is called component form)
magnitude
length of a vector
usually you can use pythagorean theorum to find this.
direction
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
tan^-1(x/y)