12-1

12-1
Section 12-1 was about vectors. Vectors represent motion and have a magnitude and direction. To add vectors, you add head to tail. To add vectors algebraically, you add components. To find the magnitude of a vector, you use the formula square root of x^2 + y^2. When given two points, such as A and B, and asked to find the vector, you use the formula (x2 – x1, y2 – y1).
Having these few little notes, let’s try an example.

EXAMPLE 1: Given A(6,4) and B(8, 9), find the vector AB.
A). According to the notes above, we’re going to use the last formula.
B). First, subtract the x’s (8-6) = 2
C). Now, subtract the y’s (9-4) = 5
D). Your vector is (2,5)

EXAMPLE 2: Find the magnitude of EXAMPLE 1’S answer. **MAGNITUDE HAS TO BE WITH A VECTOR!
A). Since we’re finding the magnitude, use the square root formula.
B). square root 2^2+5^2 = square root 4 + 25
C). Your magnitude is square root 29