Section 11.4 Example 2
Given vectors u and v, find: a) u + v, b) u - v, c) 2u and d) 3u - 4v
Section 11.5 Example 4
a) Show that the vectors AB and BC are parallel. b) Find the midpoint of vector AB
Scalar/Dot Product Exploration
1. Move the endpoints of the vectors. 2. Observe the value of the scalar/dot product. 3. What relationship(s) can you see between the vectors and the scalar/dot product? |
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Cross Product: Introduction
[b][color=#980000]The cross product [/color][/b]of any 2 vectors [b]u[/b] and [b]v[/b] is yet [b][color=#980000]ANOTHER VECTOR! [/color][/b][br][br]In the applet below, vectors [b]u [/b]and[b] v[/b] are drawn with the same initial point. [br][br]The [b][color=#980000]CROSS PRODUCT[/color][/b] of u and v is also shown [b][color=#980000](in brown)[/color][/b] and is drawn with the same initial point as the other two. [br][br]Interact with this applet for a few minutes by moving the[b][color=#bf9000] initial point[/color][/b] and [b][color=#bf9000]terminal points[/color][/b] of both vectors around. [br][br]Then, answer the questions that follow.
1.
Use GeoGebra to measure the angle at which the line containing [b]u[/b] intersects the line containing the [b][color=#980000]cross product [/color][/b]vector. What do you get?
2.
Use GeoGebra to measure the angle at which the line containing [b]v[/b] intersects the line containing the [b][color=#980000]cross product [/color][/b]vector. What do you get?
3.
Given your responses for (1) and (2) above, what can we conclude about the [b][color=#980000]cross product[/color][/b] of any two vectors with respect to both individual vectors themselves?
4.
Is it possible to position vectors [b]u[/b] and [b]v[/b] so that their [b][color=#980000]cross product = the zero vector[/color][/b]? If so, how would these 2 vectors be positioned?
5.
How would vectors [b]u [/b]and [b]v[/b] have to be positioned in order for their [b][color=#980000]cross product[/color][/b] to have the greatest magnitude? Use GeoGebra to help informally support your conclusion(s).