y=x-In(x+1)

y=x-In(x+1)

If y '= x / (x + 1), then y' = 0, then x = 0, if - 1

What does Σ mean in mathematics?

Capital Sigma is the sum sign used in mathematics

Always △ = what? I'm confused? It's not geometry
How to read this? Pinyin II
How to use discriminant to determine the value range.
Who knows?
And I have to give you an example to understand
I did a set problem
Given the set a = {x I x > 0, and X is contained in R}, B = {x ^ 2-x + P = 0}, and B is a subset of a, the problem of finding the value range of real number P is solved

Discriminant, yes