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# limit (cos(1\x))|tan x| x--> .5pi Watch

1. 1. having a hard time figuring out. I know the answer if infinite but having a hard time proving it

2. tan x = cot (.5pi - x) did not help

3. tried substituting t = 1\x got stuck

thanks
2. What does cos(1/x) tend to (hint: Use the continuity of cos(1/x) in some interval past 0)? Call this value a. Then there is a delta>0 such that cos(1/x)>a/2 for x in the delta neighbourhood of pi/2.
3. Are you trying to find ?

Use the fact that exists and is finite.

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Updated: December 6, 2010
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