Is Sqrt(x^2) Always Equal to |x|?

  • Thread starter Thread starter TyErd
  • Start date Start date
  • Tags Tags
    Function Modulus
Click For Summary
The discussion centers on the mathematical expression sqrt(x^2) and its equivalence to |x|. While sqrt(x^2) yields a positive value, it represents the principal square root, which is always non-negative. The confusion arises from the fact that while x can be negative, the square root function only returns the positive root, thus aligning it with |x|. The example of plugging in -10 illustrates that sqrt(100) equals 10, reinforcing the point that sqrt(x^2) does not equal x for negative values. Ultimately, sqrt(x^2) is always equal to |x|, reflecting the nature of square roots and absolute values.
TyErd
Messages
297
Reaction score
0
Okay, when I enter into the calculator sqrt(x^2) it equals |x|. Since when? I thought sqrt(x^2) equals x and then when you go to sketch it, it will be a positive diagonal line through the origin whereas |x| is a reflection at the origin.
 
Physics news on Phys.org
A number squared is always positive. So if you plug in -10 you get sqrt(100) which is 10.
When you cancel out the square and the square root in a problem you do that because you're looking for the principle root aka the positive one.
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 32 ·
2
Replies
32
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 15 ·
Replies
15
Views
2K
  • · Replies 23 ·
Replies
23
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
Replies
5
Views
2K
  • · Replies 23 ·
Replies
23
Views
2K
  • · Replies 12 ·
Replies
12
Views
3K
Replies
8
Views
4K