# Geometry and algebra

• Sep 2nd 2008, 02:56 PM
Apprentice123
Geometry and algebra
find the equation and build the place geometric

1) located 4 units of the x axis

I do not understand. The answer is a cylinder of equation: $y^2+z^2-16=0$
As located 4 units of the x axis can form a cylinder?

2) located 3 units the front of the plan yoz and the 5 units up the plan xoy

The answer is a straight x=3; x=5. As i build the place geometric?
• Sep 2nd 2008, 06:29 PM
horseypie
Quote:

Originally Posted by Apprentice123
find the equation and build the place geometric

1) located 4 units of the x axis

I do not understand. The answer is a cylinder of equation: $y^2+z^2-16=0$
As located 4 units of the x axis can form a cylinder?

well, think about 2d spaces. the geometric representation of the set of numbers 4 units from the x axis (both in the positive and negative directions) would be two lines, would it not? because along the lines y=4 or y=-4, it is constantly 4 units from the x-axis.

extend this to 3d space now...can you start to see the cylinder?

and im not sure about the second question sorry...the notation is kinda throwing me
• Sep 3rd 2008, 05:52 AM
Apprentice123
Thank you. More I can not see in the axle: x, y and z.

The cylinder would be parallel to the axis z?

The second issue is a straight. With x=3 and z=5