Unraveling the Mystery of y=1+x+x^3

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y=1+x+x3I just don't know where to begin...
I've always struggled with domains and ranges.

Even if you could just point me in the right direction, that would be great!

Thanks.
 
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The domain is the set of all possible x values for your function which don't cause problems. Think about this, are there any x values which your function will have a problem?

As for the range, it's the set of all possible y values your function can take on. Do your y values take on all of the real numbers or are there some which are not included?
 
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Look at what happens to y as x goes to infinity and as x goes to negative infinity. This is problem is much simpler than I suspect you realize! If the problem were about the inverse function, that would be another matter.
 
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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