arccot(0)
the number whose cotangent is zero since \[\cot(x)=\frac{\cos(x)}{\sin(x)}\] it is also the number whose cosine is zero
pi/2
that will do it
so arccot(-1)
the number whose cosine is -1?
no, it is the number whose COTANGENT is \(-1\)
the reason it worked for the first answer is because a fraction is only zero if the numerator is zero so since \[\cot(x)=\frac{\cos(x)}{\sin(x)}\] it is only zero if \(\cos(x)=0\)
but for that one you need to know where \[\frac{\cos(x)}{\sin(x)}=-1\]
it is where cosine and sine are the same number, but of opposite sign
3pi/4
7pi/4
careful here
it is \(-1\) and an infinite number of places, you have to find the one in the right range
eek what is the range?
ok you have a function that is periodic, so it is certainly not one to one in order to make the inverse a function, you have to restrict the range of the inverse so that everyone gets the same answer notice that you provided two answers, but as a function it can only have one output per input
i believe traditionally the range of arccotangent is \([0,\pi]\)
so your first answer of \(\frac{3\pi}{4}\) is the right answer, the second answer is not right, because it is not in the range or arccotangent
okay yes.. I remember that.
so that claculators can work :-)
you should help me:)))
lol also so you have a well defined function
so, how would I approach arccot(sqrt3)
it is where you have \[\frac{\frac{\sqrt{3}}{2}}{\frac{1}{2}}\] for \[\frac{\cos(x)}{\sin(x)}\]
pi/6
i.e. where \[\cos(x)=\frac{\sqrt{3}}{2}\] and \[\sin(x)=\frac{1}{2}\] a very familiar pair
yes
you make it seem so easy!
last one..
arctan(tan(5pi/4))
then I have about 50 more to do on my own :-\
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