Is the point where some region of the lithosphere reaches its ultimate elevation and stops rising.

Isostatic balance

Explanation:

Just like an iceberg floats on water with parts of it submerged in water, the same is for the crust floating on the dense ‘liquid’ mantle. The heavier a part of the crust is, the more it is submerged into the mantle in the local region. Different regions of the lithosphere  have different equilibriums depending on the local mass of the crust.

answer-

the statement that f(x) = |x+a| + b has exactly one x-intercept is sometimes correct.

solution-

it solely depends on b, whether the function will have one or two or zero x intercept.

this plot of the given function, f(x) = |x+a| + b will be the basic absolute value graph i.e v shape, with vertex translated to (-a, b), instead of origin.

1-   if b is zero, the graph will have exactly one x-intercept, at x= -a

2- if b is positive, the whole graph will be above the x-axis, hence it will have no x-intercepts.

3- if b is negative, the graph will be below the x-axis, hence it will have two x-intercepts.

∴ the statement is sometimes true.