Feldoh said:2 = |sqrt(4)|
luxiaolei said:2 = sqrt(4) = sqrt(-1*-1*4) = sqrt(-1)*sqrt(-1)*sqrt(4) = -1*sqrt(4) = -2 ?
Where am I wrong? sqrt(4) = +2 or -2 in the last step? but see sqrt(4)=-1*sqrt(4), still wrong..
Thanks in advance
Unit91Actual said:The real problem here lies in the first step, not the last. 2 is a solution to √4, but is not the solution. Your conundrum has simply re-stated that -2 is also a solution to √4. This string of equations does not prove that 2 = -2 (obviously), only that the solution to √4 is non-unique. Good luck!
willem2 said:[itex] x^2 = 4 [/itex] has two solutions, but sqrt(4) means the positive solution of this equations.
The other one is -sqrt(4).
2 = sqrt(-1 * -1 * 4) is OK, but the next step is not since sqrt(A*B) = sqrt(A) * sqrt(B) is only valid if A and B are >= 0
"sqrt" is an abbreviation for "square root". It is a mathematical operation that finds the number which, when multiplied by itself, gives the given number. For example, the square root of 4 is 2 because 2 x 2 = 4.
This is because the square root function can have both positive and negative solutions. For any positive number, there are two numbers that can be multiplied by itself to get that number - one positive and one negative. In this case, both 2 and -2 can be squared to give 4.
To solve this equation, simply take the square root of both sides. This will give you the two solutions: +2 and -2. So, the equation can be rewritten as "sqrt(4) = 2 or -2".
No, there is no specific order to solve equations like this. However, it is important to understand the properties of square roots and follow the correct mathematical steps to get the correct solutions.
You can check your solutions by substituting them back into the original equation. For example, if you plug in +2 for "sqrt(4)" in the original equation, you should get 2 = 2 which is a true statement. Similarly, if you plug in -2, you should get -2 = -2. This confirms that both solutions are correct.