McGraw Hill Glencoe Algebra 2, 2012
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McGraw Hill Glencoe Algebra 2, 2012 View details
5. Operations with Radical Expressions
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Exercise 48 Page 420

If n is an odd number, then the radical expression sqrt(a^n) simplifies to a. If n is even, the expression sqrt(a^n) simplifies to |a|.

2a^2c^4sqrt(3ab^3)

Practice makes perfect

For any real number a, the radical expression sqrt(a^n) can be simplified as follows. sqrt(a^n)= a if n is odd |a| if n is evenSince the radical is a real number and the root is even, the expression underneath the radical is positive. Otherwise, the radical would be imaginary. With this in mind, let's consider the possible values of the variables a, b, and c.

  • In the radical, the index is even and the exponents of a and b are odd. Therefore, in order for this radical expression to result in a real number, a and b must be non-negative.
  • In the radical, the index is even and the exponent of c is even. Therefore, the expression will be real whether the value of c is positive, negative or equal to 0.

This means that if we remove a or b from the radical, we will not need absolute value symbols. However, we would need them if we removed c from the radical. We can simplify the radical by writing the expression inside as powers with exponents equal to the index of the radical using the Product Property of Radicals.

sqrt(48a^9b^3c^(16))
sqrt(16 * 3a^9b^3c^(16))
sqrt(2^4 * 3a^9b^3c^(16))
sqrt(2^4 * 3a^(1+8)b^3c^(16))
sqrt(2^4 * 3 a a^8b^3c^(16))
sqrt(2^4 * 3 a a^(2 * 4)b^3c^(4 * 4))
sqrt(2^4 * 3 a (a^2)^4 b^3 (c^4)^4)
sqrt(2^4(a^2)^4(c^4)^4 * 3ab^3)
sqrt((2a^2c^4)^4 * 3ab^3)
sqrt((2a^2c^4)^4) * sqrt(3ab^3)
2a^2|c^4|sqrt(3ab^3)
2a^2c^4sqrt(3ab^3)

The simplest form of the expression is 2a^2c^4sqrt(3ab^3).