Graph the following function: y=csc(1/2x) find the domain, range, period, even/odd function, and asymptotes
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is this \[\csc(\frac{1}{2x})\] or \[csc(\frac{1}{2}x)\]?
the 2nd one
can you help?
yeah i hope
\[\csc(\frac{x}{2})=\frac{1}{\sin(\frac{x}{2})}\]
so range is from \[-\infty\] to \[\infty\]
sine is odd which means \[\sin(-x)=-\sin(x)\] and therefore this one is odd too
of course you cannot divide by zero, therefore we have to make sure that \[\sin(\frac{x}{2})\neq0\]
\[sin(x)=0\] means \[x=...-3\pi,-2\pi,-\pi,0, \pi, 2\pi, 3\pi...\]
we have \[sin(\frac{x}{2})=0\] giving \[\frac{x}{2}=k\pi\] and therefore \[x=2k\pi\] so domain is all real numbers except \[x = 2k\pi, k\in Z\]
ok i made a mistake earlier when i said range was all real numbers. sine is bounded above by 1 and below by -1 so this function is never between -1 and 1. in other words the domain is \[(-\infty,-1)\cup (1,\infty)\]
how is it so far?
except of course for my mistake!
I am taking notes as we go, thank you so much
well don't write the range is all real numbers. delete that from your notes!
ok thank you so range is ?
\[(-\infty,-1]\cup [1,\infty)\]
oh excuse me, i wrote that as the domain
it is -1 when \[sin(\frac{x}{2})=-1\]and 1 when \[\sin(\frac{x}{2})=1\]
otherwise \[-1<\sin(\frac{x}{2})<1\] so \[\frac{1}{\sin(\frac{x}{2})}>1\] or \[\frac{1}{\sin(\frac{x}{2})}<-1\]
what is left? asymptotes. we have found those. the function is undefined at \[x=2k\pi, k\in Z\] and so those are the asymptotes
and finally the period! we know that the period of sine is \[2\pi\] so the period of \[\frac{1}{\sin(x)}\] is also \[2\pi\] and therefore the period of \[\frac{1}{sin(\frac{x}{2})}\] is \[4\pi\]
and that takes care of all the questions yes?
unless of course you would like to graph it and see what it looks like
yes, thank you so much, i have one problem left if you have timeo look at it
go ahead,
y= tan(\[\pi\]x)+1
that is all suppose to be in a line
that is all suppose to be in a line
\[tan(\pi x)+1\]
?
ok this one is much easier
tangent is odd, but this is not odd because of the 1 outside
in other words if \[f(x)=\tan(x)+1\] then \[f(-x)=\tan(-x)+1=-\tan(x)+1\neq -f(x)\]
this one does have range all real numbers because tangent has range all real numbers.
domain we find as before; \[tan(\pi x)+1=\frac{sin(\pi x)}{cos(\pi x)}+1\] and since you cannot divide by 0 we have to make sure that \[\cos(\pi x)\neq 0\]
\[\cos(x)=0\] means \[x=...-\frac{5\pi}{2},-\frac{3\pi}{2},-\frac{\pi}{2},\frac{\pi}{2}, \frac{3\pi}{2}, \frac{5\pi}{2}, ...\]
so \[cos(\pi x)=0 \] means \[x=-\frac{5}{2}, -\frac{3}{2}, -\frac{1}{2},\frac{1}{2},\frac{3}{2},\frac{5}{2}...\]
more succinctly written as \[x\neq \frac{2k+1}{2}, k\in Z\]
those are you asymptotes as well
and finally the period of tangent is \[\pi\] so the period of \[\tan(\pi x)\] is \[\frac{\pi}{\pi}=1\]
and that is that. except for the graph which is here http://www.wolframalpha.com/input/?i=tan%28pi+x%29%2B1
is this even or neither
no not even or odd.
tangent is odd, but the +1 at the end throws it off
and domain is
all real numbers except \[x=\frac{2k+1}{2}, k\in Z\]
in other words all numbers except 1/2,3/2,5/2,...
odd integers divided by 2
ok and is there a way to look at the graph
i sent it i think
oh im soryy mine did not show a graph
those vertical lines are just asymptotes not part of the graph. did ou see the second one?
yes thank you is ther an email adress that i can contact you at when i need additional help
you can try me at satellite73.openstudy@gmail.com
thank you alot i really appreciate it
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