Pearson Algebra 2 Common Core, 2011
PA
Pearson Algebra 2 Common Core, 2011 View details
6. Analyzing Data
Continue to next subchapter

Exercise 42 Page 718

If a^n=b, where a and b are real numbers and n is a positive integer, then a is an n^\text{th} root of b. How many real n^\text{th} roots are there for positive b if n is even?

± 11/4

Practice makes perfect

If a^n= b, where a and b are real numbers and n is a positive integer, then a is an {\color{#009600}{n}}^\text{th} root of b. In our case, we want to find all the real 2^\text{nd} roots of 12116. a^2= 121/16 Because n=2 is even and b= 12116 is positive, there are two 2^\text{nd} roots of 12116. Positive Root:& a_1= sqrt(121/16) Negative Root:& a_2=-sqrt(121/16) Let's start with the positive root. Since the 2^\text{nd} roots are squares, we will first write b= 12116 as a power with an exponent of 2.

a_1=sqrt(121/16)
a_1=sqrt(11^2/4^2)
a_1=11/4

We found the positive 2^\text{nd} root of 12116, which also gives us the negative root. &Positive Root: a_1= 114 &Negative Root: a_2=- 114