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9.4 Vectors. Chapter 9 Right Triangle Trig. Vector : any quantity with magnitude (size) and direction Use an arrow for vector: KW. Magnitude : corresponds to the distance from initial point K to the terminal point W.
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9.4 Vectors Chapter 9 Right Triangle Trig
Vector: any quantity with magnitude (size) and direction Use an arrow for vector: KW Magnitude: corresponds to the distance from initial point K to the terminal point W You can also use an ordered pair (x, y) in the coordinate plane for a vector. The magnitude and direction correspond to the distance and direction from the origin.
Example 1, pg 490 Describe OL as an ordered pair. Give the coordinates to the nearest tenth. x O 50 y 65 L
Example 1b, pg 491 Describe the vector as an ordered pair. Give the coordinates to the nearest tenth. 51 y 65 x
Example 2, pg 491Describing a Vector Direction Use Compass directions to describe the direction of each vector. a. b. N N 35 W E W E 25 S S
Example 2, pg 491Describing a Vector Direction Sketch a vector that has the direction 30 west of north. Give a second description for the direction of this vector. N 30 E W S
Example 3, pg 491Aviation An airplane lands 40 km west and 25 km south from where it took off. The result of the trip can be described by the vector (-40, -25). Use distance and direction to described this vector a second way. N -40 W E x -25 c S
Example 3b, pg 491 A small airplane lands at a point 246 mi east and 76 mi north of the point from which it took off. Describe the magnitude and the direction of its flight vector.
Example 3b, pg 491 A small airplane lands at a point 246 mi east and 76 mi north of the point from which it took off. Describe the magnitude and the direction of its flight vector. N 76 mi x W E 246 mi y S
Adding Vectors You can also use a single lowercase letter, such as u, to name a vector. This map shows vectors representing a flight from Houston to Memphis with a stopover in New Orleans. Memphis The vector from Houston to Memphis is called the sum or resultant of the other two vectors. w = u + v w v New Orleans Houston u
Adding Vectors You can add vectors by adding their coordinates. You can also show the sum geometrically. Example 4, pg 492 Vectors a (4, 3) and c (-1, 2) are shown in the diagram. Write the sum of the two vectors as an ordered pair. Then draw e, the sum of a and c. (4, 3) + (-1, 2) = 4 + (-1), 3 + 2 = (3, 5)
Adding Vectors Write the sum of the two vectors (2, 3) and (-4, -2) as an ordered pair. 2 + (-4), 3 + (-2) (-2, 1)
Real-World ConnectionNavigation, Example 5, pg 493 A ferry shuttles people from one side of a river to the other. The speed of the ferry in still water is 25 mi/h. The river flows directly south at 7 mi/h. If the ferry heads directly west, what are the ferry’s resultant speed and direction? N w E S
Questions? Homework: pg 493 1-28