Page 144 - Excel Workbook for Dummies

14_798452 ch09.qxp 3/13/06 7:52 PM Page 127
Chapter 9: Using Math Functions 127
Finding Products, Powers, and Square Roots

Although you can create formulas that multiply values using the asterisk (*) operator
as well as those that raise a number to a particular power by using the caret (^), Excel
also includes PRODUCT and POWER functions that perform these types of calcula-
tions for you. And for those times when you need to find the square root of a value,
the program includes a SQRT function. These three Math functions work with the fol-
lowing arguments:
PRODUCT(number1,number2, . . .) where the number1, number2 arguments are
the values you want to multiply with one another
POWER(number,power) where the number argument is the value you want to
raise the power specified by the power argument
SQRT(number) where the number argument is the value for which you want the
square root

Try It

Exercise 9-2: Building Formulas with the PRODUCT, POWER, and SQRT
Functions

Open the Exercise9-2.xls workbook file in your Chapter 9 folder in the My Practice
Spreadsheets folder inside My Documents on your hard disk or in the Excel
Workbook folder on the workbook CD-ROM. This file contains a Misc. Math Formulas
worksheet where you can practice using the PRODUCT, POWER, and SQRT functions
in a couple of tables:

1. Position the cell cursor in cell D3 and construct a formula using the PRODUCT
function that multiplies the price in B3 by the quantity in cell C3.
2. Format the computed amount in cell D3 with the Currency Style format and then
copy this formula down to the cell range D4:D5.
3. In cell B9, construct a formula that squares the value in cell A9 and then copy
this POWER formula down to the cell range B10:B11.
4. In cell C9, construct a formula that cubes the value in cell A9 and then copy this
POWER formula down to the cell range C10:C11.
5. In cell D9, construct a formula that finds the square root of the value in cell A9
and then copy this SQRT formula down to the cell range D10:D11.
Cell D11 returns a #NUM! error value in the cell because the SQRT function
cannot compute square roots for negative numbers (multiplying one negative
number by another always results in a positive product).
To avoid the #NUM! error in this formula, you can nest the ABS function that
returns the absolute value of cell A11 (which is always positive) inside the SQRT
function as follows:

=SQRT(ABS(A11))
6. Edit the original formula in cell D9 by positioning the insertion point between the
T in SQRT and the open parenthesis. Type (ABS and then position the insertion
point between 9 in A9 and the close parenthesis, and then type another close
parenthesis before clicking the Enter button on the Formula bar.
The edited formula should appear on the Formula bar as follows:
=SQRT(ABS(A9))