(adsbygoogle = window.adsbygoogle || []).push({}); Prove that cos:R-->[-1,1] is continuous at every a∈R

1. The problem statement, all variables and given/known data

Prove that cos:R-->[-1,1] is continuous at every a∈R

2. Relevant equations

N/A

3. The attempt at a solution

If the function is right continuous at -1, and left continuous at 1, then should the function be continuous in the interval? so the limit of cos(x) as it approaches -1 from the right towards -1 should be the same as cos(-1), and vice versa for the other side. Please confirm or deny this.

Thanks in advance,

Charismaztex

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# Homework Help: Prove that cos:R->[-1,1] is continuous at every a∈R

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