Algebra Know-It-ALL

Chapter 29

1. We can use the property of common logarithms that converts a product into a sum:

log 10 xy= log 10 x+ log 10 y

In this case, x= 2.3713018568 and y= 0.902780337. If we use the calculator found in

the Windows computer operating system:

log 10 (2.3713018568 × 0.902780337)

= log 10 2.3713018568 + log 10 0.902780337

≈ 0.37498684137 + (−0.0444179086)

≈ 0.37498684137 − 0.0444179086

≈ 0.3305689328

This is the common logarithm of the product we wish to find. If we find the common

antilogarithm of this, we’ll get the desired result. Inputting this to a calculator and then

rounding to three decimal places:

antilog 10 (0.3305689328) ≈ 2.141

Chapter 29 713

x

y

(1,0)

Figure C-8 Illustration for the solution

to Prob. 10 in Chap. 28.