Math
posted by Luci .
I'm supposed to evaluate the following equation in the real number system f possible : (9)^1/2.
The answer says it's not possible; why, I don't understand this.

Math 
Count Iblis
The problem is really how to define fractional powers like x^(1/2).
You want it to define in such a way so that the usual rules for taking powers still hold. E.g.:
(x^a)^b = x^(ab)
This means that you want to define
x^(1/2) such that:
(x^(1/2))^2 = x
So, x^(1/2) should be the square root of x. But this is only defined for positive x. The square of a real number is always positive, so if x is negative, no real number can be its square root. 
Math 
Luci
oh, okay, I see; thank you very much! :D
Respond to this Question
Similar Questions

math,correction
the problem reads: evaluate sqrt (4) if possible. my answer: sqrt (4)<0 therefore this is not a real number looks correct you cannot take the square root of a negative number in the real number set. Have you learned the imaginary … 
Adv. Math.
Find the number of possible negative real zeros for f(x)=6+x^4+2x^25x^312. Answer: 0 2) Approximate the real zeros of f(x)=2x^43x^22 to the nearest tenth. Answer: no real roots 
Math  Real number system
Solve the following equation in the real number system. Please show all of your work. x^4 + 6x^3 + x^2  24x  20 = 0 Help!!!! 
college algebraplease help
what does Descartes rule of signs tell you about the possible number of positive real number zeros and the possible number of negative real zeros of the function? 
algebra
Coulld someone take the time and check my answers please. 11) without graphing is the system independent, dependent, or inconsistent? 
Math Algebra
Use Descartes' Rule of Signs to determine the possible number of positive real zeros and the possible number of negative real zeros for the function. 1. 9x^65x^42x^3+8x^24x=0 2. 9x^4+5x^32x^2+4x3=0 
Calculus (check my answers)
10) Use the information to evaluate and compare delta y and dy. y=2x^4, x=2 and delta x=dx=0.01 MY ANSWER: dy=.32 and delta y=.3224. Are they supposed to be negative, and how do I compare those in words? 
College algebra
Use descartes rule of sign to determine the possible number of positive real zeros and possible number of negative 6x^56x^4+7x^38 
math
Solve the equation for x. For each of the following problems is it possible for x to be equal to: 1? 
Math
1.) Is it possible for a composite number to have more than one prime factorization?