TRIANGLES:
1. Law of Sines
NOTE: Don’t forget about the Ambiguous Case (SSA or ASS)
2. Law of Cosines (use this when you have SAS or SSS)
NOTE: I only use the third one in standard form. You can memorize whichever you prefer.
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VECTORS:
1. This is the component form of a vector v, written as
See the box below to find magnitude.
Use these if you are given two points or the components.
If you are given the magnitude and the direction angle, use this instead:
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2. To add vectors, draw them head to tail.
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3. A unit vector is a vector that is a vector that is one unit long in the same direction as a given vector.
4. To find the direction angle of a single vector, use SOH CAH TOA which leads you to tan x = v2/v 1
Then do arctan to find the angle.
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5. The dot product between two vectors = u1 v1 + u2 v2
Note: If the dot product = 0, then the two vectors are orthogonal (perpendicular).
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6.
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TRIGONOMETRIC FORM OF A COMPLEX NUMBER: