Which octant/plane
Distance/Midpoint of 2 points
Spheres
More Spheres
Harder Topics (at your own risk)
100

Which octant/plane does (1, 1, 1) belong in

Octant 1 because all of the coordinates are positive

100

Find distance between (0, 0, 1) and (0, 0, 100)

99

100

Find center of the sphere: x^2+y^2+(z-1)^2=100

(0, 0, 1)

100

Find radius: (x-1)^2+(y-2)^2+(z+1000)^2=1

radius is 1
100

Determine whether the points make a straight line and show work

a) (1, -2, 3)

b) (4, 4, -3)

c) (6, 8, 7)

the pattern from a to b and b to c should stay consistent. To get to a to b, the 3-d vector would (3, 6, -6). To get to b to c, then vector is (2, 4, 10). Therefore, since pattern is inconsistent, this isn't collinear. 

200

Which octant/plane is the (0, 0, 0)

None, it's the origin, duh...

200

What is the distance and midpoint between (1, 1, 1) and (1, 2, 3)

Distance= (0+1+4)^(1/2)=(5)^(1/2)

Midpoint= (1, 1.5, 2)

200

What is the center and radius: (x-100)^2+(y+99)^2-(z+0.01)^2=2.25

Center: (100, -99, -0.01)

Radius: 1.5

200

What is the distance between the center of the given sphere and the x-axis: (x-1.09)^2+(y-1000)^2+(z+256)^2=2500

the center is (1.09, 1000, 256.23). the x coordinate doesn't matter (since you're looking to compare with x-axis). Therefore, we have to find the distance between the axis with respect to only y and z. Therefore, d=((1000-0)^2+(-256-0)^2)^(1/2)=1032.248

300

Which octant/plane does (0, 5, 2)

the yz plane because there's no x coordinate

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