sqrtx1x22y1y22z1z22
sqrtx1x22y1y22z1z22 is not a standard mathematical symbol. It appears to be a concatenation of the word sqrt with several subscripted terms x1, x2, y1, y2, z1, z2, and may be intended to denote a square root of a product involving those variables. Because the notation is ambiguous without parentheses, it is common to consider two readings.
One reading is sqrt(x1 x2 y1 y2 z1 z2), the square root of the product of six
A second reading is the product of three square roots: sqrt(x1 x2) sqrt(y1 y2) sqrt(z1 z2). This
In either interpretation, explicit parentheses are advised to avoid ambiguity. For example, sqrt((x1 x2)(y1 y2)(z1 z2))
Typical contexts include algebraic manipulation, geometric interpretations of products of coordinates, or programming notation where clarity