Continuity With Piece Wise Functions

Michele Nunes
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Homework Statement


Determine all values of the constant a such that the following function is continuous for all real numbers.
f(x) = ax/tan(x), x ≥ 0
= a2 - 2, x < 0

Homework Equations

The Attempt at a Solution


I tried so many different ways to get the first part of the function to be defined at 0 but nothing worked, I tried manipulating it with a bunch of trig identities and no matter what, that first part is always undefined at 0 so I don't know how the function can ever be continuous if that first part of the function is always going to be undefined at 0 and I can't remove it.
 
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Michele Nunes said:

Homework Statement


Determine all values of the constant a such that the following function is continuous for all real numbers.
f(x) = ax/tan(x), x ≥ 0
= a2 - 2, x < 0

Homework Equations

The Attempt at a Solution


I tried so many different ways to get the first part of the function to be defined at 0 but nothing worked, I tried manipulating it with a bunch of trig identities and no matter what, that first part is always undefined at 0 so I don't know how the function can ever be continuous if that first part of the function is always going to be undefined at 0 and I can't remove it.
This limit will be helpful:
$$\lim_{x \to 0} \frac {\sin x} x = 1$$

Note that ##\frac{ax}{\tan(x)} = a \frac x {\frac{\sin(x)}{\cos(x)}}##
 
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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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