McGraw Hill Glencoe Algebra 2, 2012
MH
McGraw Hill Glencoe Algebra 2, 2012 View details
6. Common Logarithms
Continue to next subchapter

Exercise 29 Page 496

{ n | n > 0.6667 }

Practice makes perfect

To solve the given exponential inequality, we will use the Inequality Property of Logarithmic Functions.

Inequality Property of Logarithmic Functions

&Ifb > 1, log_b x > log_b y if and only if x > y. &Ifb > 1, log_b x < log_b y if and only if x < y.

Using this property, we can rewrite the exponential inequality as a logarithmic inequality. 6^(3n) > 36 ⇔ log 6^(3n) > log 36 To solve the above logarithmic inequality, we need to recall the Power Property of Logarithms.

Power Property of Logarithms

log_b m^p = p log_b m, where m and b are positive numbers, with b≠ 1.

Let's use it and solve the inequality!

log 6^(3n) > log 36

log_()(a^m)= m* log_()(a)

3n log 6 > log 36
3n log 6 > log 6^2

log(a^m)= m*log(a)

3n log 6 >2 log 6
3n >2
n > 2/3
n > 0.6667

Finally, we can write our answer in set-builder notation. { n | n > 0.6667 }