Graphs - Increasing/Decreasing Intervals

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Homework Statement


#1: The graph of f' is shown. Find the intervals on which f increases.

#2: The graph of f'(x) is shown. Give the interval(s) where the graph in concave down.


Homework Equations


Not sure.


The Attempt at a Solution


#1: Well, I thought it was (-infinity, infinity), but I got incorrect. X and Y are both increasing.

#2: I got (0, infinity) incorrect, which confuses me, because I thought concave down was like an upside down U.
 

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ceity said:

Homework Statement


#1: The graph of f' is shown. Find the intervals on which f increases.

#2: The graph of f'(x) is shown. Give the interval(s) where the graph in concave down.


Homework Equations


Not sure.


The Attempt at a Solution


#1: Well, I thought it was (-infinity, infinity), but I got incorrect. X and Y are both increasing.

#2: I got (0, infinity) incorrect, which confuses me, because I thought concave down was like an upside down U.

The problem says those are the graphs of f'(x) and then the first questions asks about where f(x) is increasing, not f'(x). How can you tell if f(x) is increasing from knowing f'(x)? It's likely the second one means the same though they don't spell out which graph is supposed to be concave. It also might be a stretch claiming you know what the graph looks like near infinity when they are only showing you a small part.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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