2006-09-08 04:51:10 · 22 answers · asked by Hacker 3 in Science & Mathematics ➔ Mathematics
2b or not 2b... that is the question
2006-09-08 04:56:37 · answer #1 · answered by Behind Blue Eyes 3 · 4⤊ 1⤋
A lot of people fall down in this hole.
The square root is always a positive number. There is only a value, because sqrt(x) is the output of the function y = sqrt(x) and a function admits only a input for each input.
That is sqrt(9) = 3 and not +3 or -3 ... that is a mistake because when we are solving an equation like x^2=9 we obtain two answers x= +3 and x=-3. The last is right not because we evaluate the sqrt of 9, but because x has 2 as exponent.
There is a rule for simplifying sqrt(x^2) = x but this rule is true only if x is non-negative numbers. If x can assume negative values, the rule is sqrt(x) = abs(x).
In your case... we don´t know if b is positive or negative, so the only right answer is sqrt(4b^2) = abs(2b).
If you know that b is non-negative, then sqrt(4b^2) = 2b
2006-09-08 13:57:37 · answer #2 · answered by vahucel 6 · 1⤊ 1⤋
Square root of 4b² = 2b.
Proof 2b * 2b = 2*b*2*b
= 4*b*b
= 4b²
However since its an even root the answer can also be -2b²
since the multiplication of 2 negative intergers will result in a positive interger.
Explanation.
(-2b²) * (-2b²) = 4b²
So your answers are 2b² OR -2b².
Cheers,
2006-09-08 12:24:10 · answer #3 · answered by isz_rossi 3 · 0⤊ 0⤋
What is the square root of 4b^2?
4b^2= 2 x 2x b x b
= (2 x b)x(2 x b)
Therefore sq rt = 2 x b=2b
2006-09-08 12:01:07 · answer #4 · answered by Amar Soni 7 · 1⤊ 0⤋
The square root of a squared number is that number.
For example is you had x^2 the answer would be x.
4b^2 = 4b
2006-09-08 12:55:36 · answer #5 · answered by Rachel M 2 · 0⤊ 1⤋
Square root is always a positive number, so:
Sqrt(4b^2) = 2*abs(b)
2006-09-08 14:51:51 · answer #6 · answered by Dimos F 4 · 0⤊ 0⤋
Caution - some people don't know what they are talking about!!!
The answer is +/- 2b. (as some people have said)
You DO have negative square roots - ask anyone with an A-level in Maths! (like me for example)
2006-09-08 16:28:56 · answer #7 · answered by Chris H 1 · 0⤊ 0⤋
+/- 2b
Two roots since (-2b)^2 = (2b)^2 = 4b^2
Hope that helps!
2006-09-08 11:59:03 · answer #8 · answered by Yada Yada Yada 7 · 2⤊ 0⤋
It is + or - 2b because 2b times itself = 4b^2 and so does (-2b) times itself.
2006-09-08 11:57:03 · answer #9 · answered by hayharbr 7 · 2⤊ 0⤋
What do u mean friend, 4b^2 or (4b)^2 ?
If 4b^2, then sq. roots r (+2b) & (-2b)
If (4b)^2 then sq. roots r (+4b) & (-4b).
2006-09-08 13:21:16 · answer #10 · answered by Innocence Redefined 5 · 0⤊ 0⤋
4b or even -4b
.It can't be 2b because that's a grade of pencil.
...Hmm, 2b or not 2b, hasn't somebody else asked that?
2006-09-08 11:58:58 · answer #11 · answered by boracic1 3 · 0⤊ 2⤋