Answer:
Proof in explanation.
Step-by-step explanation:
I'm going to attempt this by squeeze theorem.
We know that is a variable number between -1 and 1 (inclusive).
This means that .
for all value . So if we multiply all sides of our inequality by this, it will not effect the direction of the inequalities.
By squeeze theorem, if
and , then we can also conclude that .
So we can actually evaluate the "if" limits pretty easily since both are continuous and exist at .
.
We can finally conclude that by squeeze theorem.
Some people call this sandwich theorem.