SOLUTION: classify the given numbers as real and rational, real and irrational, or complex (4)^1/2 + 2

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Question 594347: classify the given numbers as real and rational, real and irrational, or complex
(4)^1/2 + 2

Found 2 solutions by jsmallt9, richard1234:
Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
First we'll simplify the expression. Then we will determine the class(es) of the number.

Since 1/2 as an exponent means square root and since the square root of 4 is 2, this expression simplifies as follows:
4%5E%281%2F2%29+%2B+2+=+2+%2B+2+=+4

Complex numbers are two-part numbers: a real part and an imaginary part. They are written in the form: a + bi where "a" is the real part of the complex number and "bi" is the imaginary part of the complex number. The "i" is the name for sqrt%28-1%29 and the "a" and "b" can be any real number.

Every number I know of is a complex number! IOW there are NO numbers that are not complex. Simple numbers like 10 are just complex numbers whose imaginary parts are zero: 10 + 0i

But the phrasing of your question, "real and rational, real and irrational, or complex". makes me think that complex numbers are considered a separate class of numbers from the other two. So I am going to answer your question two ways: the correct way and the way that considers complex numbers to be separate from the other two classes.

Correct:
  • 4 is complex because it can be written as 4 + 0i and the 4 and the 0 are real numbers.
  • 4 is real because the imaginary part of 4 + 0i is zero.
  • 4 is rational because it can be written as the ratio of two integers: 4 = 4/1.
  • So the correct answer is that 4 is complex, real and rational (all three).

If it is believed (incorrectly) that complex numbers must have a non-zero imaginary part, then 4 is just real and rational.

Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
4^(1/2) + 2 = 4

4 is real and rational. Technically it is also considered complex because it can be plotted on the complex plane.