Beginning Algebra, 11th Edition

Root Key Some calculators have a key specifically marked or ; with

others, the operation of taking roots is accomplished by using the inverse key in con-

junction with the exponential key. Suppose, for example, your calculator is of the

latter type and you wish to find the fifth root of 1024. Use the following keystrokes.

1 0 2 4 INV xy 5 4

Inverse Key Some calculators have an inverse key, marked. Inverse opera-

tions are operations that “undo” each other. For example, the operations of squaring

and taking the square root are inverse operations. The use of the key varies

among different models of calculators, so read your owner’s manual carefully.

Exponential Key The key marked or allows you to raise a number to

a power. For example, if you wish to raise 4 to the fifth power (that is, find as

explained in Chapter 1), use the following keystrokes.

(^4) xy 5 1024

45 ,

xy yx

INV

INV

APPENDIX B An Introduction to Calculators 605

While you are not expected to have a graphing calculator to study from this book, we

include the following as background information and reference should your course or

future courses require the use of graphing calculators.

Graphing Calculators

=

=

2 yx^2 xy

Notice how this “undoes” the operation explained in the discussion of the exponen-

tial key.

Pi Key The number is an important number in mathematics. It occurs, for exam-

ple, in the area and circumference formulas for a circle. One popular model gives the

following display when the key is pressed. (Because is irrational, the display

shows only an approximation.)

An approximation for

Methods of Display When decimal approximations are shown on scientific calcula-

tors, they are either truncatedor rounded. To see how a particular model is programmed,

evaluate as an example. If the display shows 0.0555555 (last digit 5), the calcu-

lator truncates the display. If the display shows 0.0555556 (last digit 6), the calculator

rounds the display.

When very large or very small numbers are obtained as answers, scientific calcu-

lators often express these numbers in scientific notation (Chapter 5). For example, if

you multiply 6,265,804 by 8,980,591, the display might look like this:

The 13 at the far right means that the number on the left is multiplied by This

means that the decimal point must be moved 13 places to the right if the answer is to

be expressed in its usual form. Even then, the value obtained will only be an approx-

imation: 56,270,623,000,000.

1013.

5.6270623 13

1/18

3.1415927 p

p p

p