Find an integer which is the limit of (1-cosx)/x
as x goes to 0
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OpenStudy (yuki):
you can use the sandwitch thm
OpenStudy (amistre64):
1/x - cosx/x
OpenStudy (yuki):
or you can do L'Hospitals rule
OpenStudy (amistre64):
hopitals rule was my thought :)
OpenStudy (yuki):
if you take derivative of both top and bottom
you'll get
sin(x)
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OpenStudy (yuki):
so as x-->0, sin(x)-->0
so the answer is 0
OpenStudy (amistre64):
we can always do the long version :)
1-cos(x+h) - 1 + cos(x)
--------------------- maybe?
h
OpenStudy (anonymous):
thank you all. it's 0 as yuki said hehe
OpenStudy (amistre64):
its always been 0 lol
OpenStudy (yuki):
is you use the sandwich thm
\[-1 \le \cos(x) \le 1 \]
\[1 \ge -\cos(x) \ge -1\]
\[2 \ge 1-\cos(x) \ge 0\]
\[{2 \over x } \ge {1-\cos(x) \over x} \ge 0\]
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OpenStudy (yuki):
now if you take the limit on both sides
\[\lim_{x \rightarrow 0} {2 \over x} \ge \lim_{x \rightarrow 0}{1-\cos(x) \over x} \ge \lim_{x \rightarrow 0}{0}\]
\[0 \ge \lim_{x \rightarrow 0}{1-\cos(x) \over x} \ge 0\]
so the limit is 0