Which value is a solution for the equation
\[\cot \frac{ x }{ 2 } =0\]
cot A = cos A /sin A cot (x/2) = 0 will give you cos (x/2) / sin (x/2) = 0 ----> cos (x/2) = 0 see the unit circle and tell when is cos value = 0 ?
pi/2 and 3pi/2 ???
yes, so, x/2 = those, so, x=... ?
what?
you got , x/2 = pi/2 and x/2 = 3pi/2 these are correct, now find x
oh ok
you need general form or in the range 0,2pi ?
well the 1st one i got pi
is correct
ok now what
you need general form or in the range 0,2pi ?
whats that?
does your question say to write general form ? (if you have choices, list them)
Think about it. what is cot(x)? cot (x) = cos(x)/sin(x) Lets take 90 degrees. cos(x)/sin(x) = 0/1 = 0 270 degrees, cos(x)/sin(x) = 0/-1 = 0 So every pi/2 radians, you will get a 0. x/2 = pi/2 2x= 2 pi x = pi Now we know we're going to add a +pi for every full rotation. In finding the general form for cot(x/2)= 0 from [0,2pi] , we state that that 2*pi*n +pi will give us 0 for every full rotation from 0 to 2pi. n = 0 2 * pi *(0) + pi = pi, we start there. n = 1 2 * pi * (1) + pi = 3 pi. etc..
3pi/4 3pi/2 pi/2 3pi
i chose 3pi
and that is correct :) x/2 = 3pi/2 x = 3pi
yay!
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