How Do You Sum the Components of Vectors in Three Dimensions?

[JVeazie]

Homework Statement

[/B]
Given the following vector components of vectors C and D:
Cx = 8.10, Cy = -5.40, Cz = -7.90, Dx = 4.40, Dy = -2.50, Dz = 4.50,
find the x, y, z components of their sum.

Homework Equations

No relevant equations that I know of...[/B]

The Attempt at a Solution

I am lost completely. I do understand using (x,y) components, as well as use of the Pythagorean theorem for right triangles, etc...
The z component is throwing me off completely. Do I use the (-) as an indication of direction? Does Z represent a hypotenuse?
Im so confused.

 

[Student100]

Homework Statement

[/B]
Given the following vector components of vectors C and D:
Cx = 8.10, Cy = -5.40, Cz = -7.90, Dx = 4.40, Dy = -2.50, Dz = 4.50,
find the x, y, z components of their sum.

Homework Equations

No relevant equations that I know of...[/B]

The Attempt at a Solution

I am lost completely. I do understand using (x,y) components, as well as use of the Pythagorean theorem for right triangles, etc...
The z component is throwing me off completely. Do I use the (-) as an indication of direction? Does Z represent a hypotenuse?
Im so confused.

Z represents that you're working in $\mathbb{R}^3$, do you know what this means?