does √4=2 or does √4=+/-2?

Question

does √4=2 or does √4=+/-2. Please explain and examples would be greatly appreciated

Answer 1

squareroot(4) = 2, not +/- 2
I asked this same question to the head of the math department at the college that I attend. It is true that -2 squared is equal to 4, but that is not your question. A squared function is not one-to-one, that's why x^2=4 has two answers, -2 and 2. but squareroot of 4 is one-to-one and the answer is 2.
One-to-one means that for every input, namely (x), there is only one output, namely (y).

Answer 2

i agree with kewsworld. The square root of 4 does not give -2, even if -2 multiplied by -2 =4. I want to share some for you to differentiate.1) -2^2=-4
whereas 2) (-2)^2=4
there is a difference between the two,

Answer 3

The answer is the first one, because √4 means the "positive" square root of 4. Although if you had

x^2 = 4

and you took the square root of both sides, you WOULD put a plus or minus, and say

x = +/- √4

If, however, you were asked to solve

+/- √4, THEN you would get +/- 2.

If y = √x, you're going to get one solution for y, not 2, because, again, √ means the "positive" or "principal" square root. You're NOT going to get two solutions, otherwise this wouldn't be a function.

If y^2 = x, THEN y = +/- √x .
The +/- is the result of taking the square root of both sides of an equation, NOT of the √ function itself.

To put it in simplest terms, if you use the button √ on your calculator for the number 4, you're going to get 2, instead of two solutions. Why? Because √ means the principal square root. It's no different than why the first is true.

Answer 4

this is another fun math thing. when it is written like like you wrote it, it is equal ONLY to 2. if it is written ± (square root of ) 4 then the answer is ± 2 . if it is written - ( square root of) 4 then the answer is -2. but if it is just written (the square root of) 4 then the answer is 2. the reason this is so is because negative numbers arent always an answer to the problem, for example, in finding the missing side of a right triangle you go a^2 + b^2 = c^2. when you take the sqaure root, the answer cannot be negative. the same goes for free falls in Physics when you need to find the time an object fell, it cant fall for -5 seconds. so in answer to your question, the square root of 4 is 2. you only put negative two or ± 2 when the question specifically says so

hope i helped, vote mine best

Answer 5

The square root of 4 = +/-2 because 2*2=4 and also -2*-2 = 4

Answer 6

The answer depends on what pretense you are using.

If you simply have √4 as an expression, then the answer is 2; as you just simplify the expression

However if the √4 is in an equation (such as 4=x^2) the answer is +/- 2. The reason is b/c both 2 and -2 equivocate to 4.

Math Grammer, such an annoyance.

Answer 7

It would be sqaure root of 4 = 2. You can also write it as the square root of 4 = +2. If the square root sign had a "-" before it, the answer would be -2. If the square root sign had +/- before it, the answer could be written "+/- 2", or, "+2, -2."

Answer 8

+/-2 -2 x -2 = 4 and 2 x 2 = 4 same answer.

Answer 9

√4=+/-2

Because:

+2 * +2 = 4

-2 * -2 = 4

Answer 10

+/- 2

(-2)(-2)=4
(2)(2)=4