If f:[−1,∞)→[1,∞) is defined by f(x)=|x+1|+1, then the value of f−1(7) is

If f:[−1,∞)→[1,∞) is defined by f(x)=|x+1|+1, then the value o

1.	If f:[−1,∞)→[1,∞) is defined by f(x)=\|x+1\|+1, then the value of f−1(7) is
Answer» If $f : [- 1, \infty) \to [1, \infty)$ is defined by $f (x) = \| x + 1 \| + 1$ , then the value of $f^{- 1} (7)$ is