Microsoft Office Tutorials and References

In Depth Information

=PI()*radius*(SQRT(height^2+radius^2)+radius)

To calculate the volume of a cone, multiply the square of the radius of the base by Π, multiply by the height,

and then divide by 3. The following formula returns the volume of a cone, using cells named
radius
and
height:

=(PI()*(radius^2)*height)/3

Calculating the volume of a cylinder

To calculate the volume of a cylinder, multiply the square of the radius of the base by Π and then multiply by

the height. The following formula calculates the volume of a cylinder, using cells named
radius
and
height:

=(PI()*(radius^2)*height)

Calculating the volume of a pyramid

Calculate the area of the base, multiply by the height, and then divide by 3. This formula calculates the volume

of a pyramid. It assumes cells named
width
(the width of the base),
length
(the length of the base), and
height

(the height of the pyramid).

=(width*length*height)/3

Solving Simultaneous Equations

This section describes how to use formulas to solve simultaneous linear equations. The following is an example

of a set of simultaneous linear equations:

3x + 4y = 8

4x + 8y = 1

Solving a set of simultaneous equations involves finding the values for x and y that satisfy both equations. For

this set of equations, the solution is as follows:

x = 7.5

y = –3.625

The number of variables in the set of equations must be equal to the number of equations. The preceding ex-

ample uses two equations with two variables. Three equations are required to solve for three variables (x, y, and

z).

The general steps for solving a set of simultaneous equations follow. See Figure 10-5, which uses the equations

presented at the beginning of this section.

1.
Express the equations in standard form. If necessary, use simple algebra to rewrite the equations such that

the variables all appear on the left side of the equal sign. The two equations that follow are identical, but the

second one is in standard form: