Monday, September 2, 2013

Section 13.2, Vectors!


Vectors!

What is a vector? 
Well, it's magnitude and direction represented by an arrow!

i, j and k are all unit vectors with length 1
is in the x direction
j is in the y direction
is in the z direction


Vector Notation:

In 3-Space, vector V starts at the origin and terminates at the point (Vx, Vy, Vz), therefore it has components <Vx, Vy, Vz>. Vx indicated the magnituse of the x-component of the vector, Vy the magnitude of the y-component and Vz the z-component. 
<Vx, Vy, Vz>  can be translated anywhere along the graph. In other words, two vectors are equal if and only if their corresponding components are equal.


Properties of Vectors:


When adding or subtracting vectors, simply add/subtract the components



Figure 13.2.6: Subtracting vectors is the same as adding the negative vector


Some other properties of Vectors. They essentially follow the same principles of  everyday Math!




The resultant vector is always the sum of two vectors!

Here's an example of manipulating vectors


More Properties and Terms:



Finding a vector when given the initial point, P1, and the terminal point, P2:

In both 2 and 3 space,  the components of vector P1P2 are found by subtracting P1 from P2




Using Laws of Sines and Cosines to Find the Magnitude and Angle of a Resultant Vector:


Throwback to Trig!! #TBTT :





Red indicates usage of the Law of Cosines. Blue indicates usage of the Law of Sines


Here's an example!!



Normalizing Vectors:
(Watch Out! 
Finding the norm and normalizing 
are NOT the same!!)

How to find the Norm of a vector (which is the same as the magnitude!)

Normalizing: Creating a unit vector with the same angle as vector  V



 Heres an example!

We normalized the vector,  creating a unit vector with the components 2/3i + 2/3j - 1/3k



Here's Some More Helpful Links:



Properties of vectors (plus a little more we haven't learned yet):http://www.wyzant.com/help/math/calculus/multivariable_vectors/properties_of_vectors












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