McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
3. Simplifying Radical Expressions
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Exercise 8 Page 248

For radical expressions where the exponent of a variable inside the radical is even and the simplified expression has an odd exponent, absolute value symbols must be used.

2|mp|r^2sqrt(22mr)

Practice makes perfect

Before we attempt to simplify the given radical expression, let's consider one of the more difficult parts of correctly simplifying radicals. When the exponent of a variable inside the radical is even and the simplified expression for that variable has an odd exponent, we need to use absolute value symbols. ll sqrt(x^2)= |x| & sqrt(x^3)=x sqrt(x) sqrt(x^4)=x^2 & sqrt(x^6)=|x^3| This is because we do not want the result to be negative — the range of a square root function is all real numbers greater than or equal to 0. Now, consider the given radical expression. sqrt(88m^3p^2r^5) The exponent of m is odd, so we will not need absolute value symbols if we remove m from the radical. The exponent of p is even and, in the simplified expression, this variable will have an odd exponent. Therefore, when we remove p from the radical, we will need absolute value symbols.The exponent of r is odd, so we will not need absolute value symbols if we remove r from the radical.

sqrt(88m^3p^2r^5)
sqrt(22 (4)m^3p^2r^5)
sqrt(22(2^2)m^3p^2r^5)
sqrt(22(2^2)m^(1+2)p^2r^(1+4))
sqrt(22(2^2)m m^2 p^2 r r^4)

Now that we have simplified the factors as much as possible, let's recall the Product Property of Square Roots. sqrt(a* b)=sqrt(a) * sqrt(b), for a≥ 0,b≥ 0 Let's use this property to simplify our expression even further.

sqrt(22(2^2)m m^2 p^2 r r^4)
sqrt(22) sqrt(2^2) sqrt(m) sqrt(m^2) sqrt(p^2) sqrt(r) sqrt(r^4)
sqrt(22) (2) sqrt(m) sqrt(m^2) sqrt(p^2) sqrt(r) sqrt(r^4)
sqrt(22) (2) sqrt(m) |m| |p| sqrt(r) sqrt(r^4)

sqrt(a^m)=a^(mn)

sqrt(22) (2) sqrt(m) |m| |p| sqrt(r) r^2
2 |m| |p| r^2 sqrt(22) sqrt(m) sqrt(r)
2|m||p|r^2sqrt(22mr)

|m||p|=|mp|

2|mp|r^2sqrt(22mr)