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- Calculus 3
- Three Dimensions
3-D coordinate system
- Intro Lesson: a13:47
- Intro Lesson: b9:53
- Intro Lesson: c7:06
- Lesson: 11:29
- Lesson: 22:56
- Lesson: 32:59
- Lesson: 44:43
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- Lesson: 63:08
- Lesson: 75:10
3-D coordinate system
Lessons
3-D Coordinate System
In the 3-D Coordinate System, also denoted as R3, we have 3 axis (x,y,z). We draw the axis' in the graph like this:
Points are written in the form P=(x,y,z)
Planes
The xy-plane corresponds to all the points at which z=0.
The xz-plane corresponds to all the points at which y=0.
The yz-plane corresponds to all the points at which x=0.
These planes are sometimes called "coordinate planes".
Projection of a Point
When a point P=(x1,y1,z1) gets projected onto a plane, then the point will be on the plane.
For example, the projection of point P=(x1,y1,z1) onto the xy-plane will become (x1,y1,0).
Distance of Two Points
To find the distance between two points in R3, we use the formula:
D=(x2−x1)2+(y2−y1)2+(z2−z1)2
Where the two points are P=(x1,y1,z1) and Q=(x2,y2,z2).Other General Equations in 3D
Here are the general types of equations you might see in the 3-D Coordinate system:
- Cylinder: (x−a)2+(y−b)2=r2
Points are written in the form P=(x,y,z) - Sphere: (x−a)2+(y−b)2+(z−c)2=r2
Points are written in the form P=(x,y,z) - Plane: ax+by+cz=d
- Introduction3-D Coordinate System Overview:a)R,R2,andR3
- Axis in 1D, 2D, and 3D
- Points in 3D
- xy-plane, xz-plane, and yz-plane
b)Projection & Distance of points
- Projection of a point on a plane
- Distance between two points in 3D
- Knowing and Applying the formula
c)Graphing & Analyzing Equations
- Graphing the equation x=3 in R,R2,andR3
- Can this equation be graphed in this dimension?
- Other Equations we might see in the course
- 1.Finding Projection of Points
Find the projection of the point (−3,1,5) onto the yz-plane. - 2.Finding the Distance of Two Points
Find the distance between P1=(1,0,4) and P2=(−2,3,5). - 3.Find the distance between P1=(2,−1,−3) and P2=(4,0,1).
- 4.Graphing Equations in Different Dimensions
Graph the equation y=4 in 3D. - 5.Analyzing Equations in Different Dimensions
Determine whether the equation (x−2)2+(y−1)2=25 can be graphed in 1D, 2D and 3D. - 6.Express a 3D Shape as an Equation
Suppose a sphere is centred at (2,5,3) and the radius of the sphere is 4. Express the sphere as an equation in R3. - 7.Suppose a cylinder is centred at the origin, and the radius of the cylinder is 3 cm. In addition, the cylinder is aligned to the y-axis. Express the cylinder as an equation in R2.