What meaning 'vanish' in math [closed]

Solution 1:

Vanishing:

A quantity which takes on the value zero is said to vanish.

For example, the function f(z)=z^2 vanishes at the point z=0. For emphasis, the term "vanish identically" is sometimes used instead, meaning the quantity in question does not merely vanish by all appearances, but is mathematically identically equal to zero.

A quantity that is nonzero everywhere is said to be nonvanishing.

(mathworld.wolfram.com)