Can you help me please : lim cot(2x)/cot(3x) as x approaches to 0
can u draw the problem please
@dan815 @Michele_Laino @amistre64
find the limit of cot(2x)/cot (3x) as x approaches to 0 @israa88
cos(2x)sin(3x) -------------- sin(2x)cos(3x) we might be able to modify these if need be to get them into a more familiar form
\[\lim_{x \rightarrow 0} \tan(3x)\cot(2x)\] I guess you can use L' hopital rule
sin(a+b) = sin(a)cos(b) + sin(b)cos(a) sin(a-b) = sin(a)cos(b) - sin(b)cos(a) --------------------------------- sin(a+b) + sin(a-b) = 2 sin(a)cos(b) 1/2 (sin(a+b) + sin(a-b)) = sin(a)cos(b)
sin(3x)cos(2x) ----------- sin(2x)cos(3x) sin(5x) + sin(x) ------------- sin(5x) - sin(x)
just trying out some manipulations: sin(5x) + sin(x) - sin(x) + sin(x) ---------------------------- sin(5x) - sin(x) 2sin(x) 1 + ------------- sin(5x) - sin(x)
thank you so much @amistre64
any of this seem useful to you? its in sin so we might be able to modify it more with like 5x and x stuff
I'll try it later .. anyway thanks :) @amistre64
\[\huge \lim_{x \rightarrow 0} \frac{ \cot(2x) }{ \cot(3x) } = \lim_{x \rightarrow 0} \tan(3x)(\cot(2x)) \] You can set it up as 0/0, just another method if you want to check.
might not have had to go as far as i did, the simple sin cos definintions might be useful cos(2x)sin(3x) -------------- sin(2x)cos(3x) 2x 3x cos(2x)sin(3x) ----------------- 2x 3x sin(2x)cos(3x) 3x cos(2x) ---------- 2x cos(3x)
That's even better actually :)
yeah ...
we got the results now? :)
cos(2x) and cos(3x) to 1 x/x to 1 leaving ..... tada lol
:) Voila ! @amistre64
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