which statements in the comments are true

Question

1 if the graph of a function is always concave up, then the left-hand Reiman sums with the same subdivisions over the same interval are always less then the right-hand sums.

2 if the function f is continuous on the interval [a,b] and a doesn't equal b with a ∫ b f(x) dx = 0, then f must have at least one zero between a and b.

3 if f'(x)>0 for all x in an interval, then the function f is concave up in that interval

Answer 1

please see video