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anonymous
 4 years ago
'complex' numbers?
Suppose w6 = 64i. Determine the six values of w.
anonymous
 4 years ago
'complex' numbers? Suppose w6 = 64i. Determine the six values of w.

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anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0hm i have no idea how to even start this...

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0is this supposed to be w raised to the 6th power?

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0is this \[w^6=64i\]?

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0if so this is not so bad.

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0yes it is \[w ^{6} = 64i\]

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0you just take the 6th root, right sat?

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0hello math girl. this site is very slow for me tonight

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0figure out what number you multiply by itself 6 times

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0that gives you 64, and then stick on i on it

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0yeah just take the 6th roots. if working in degrees write \[64i=64(\cos(270)+i\sin(270))\] and then take the 6ht root of 64 which is 2 and divide 270 by 6 to get 45 so first answer is \[2(\cos(45)+i\sin(45))\]

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0where'd the trig stuff come from?

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0degrees means it is easier for me to divide and get whole number not write fractions in latex

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0i must be confused about the type of problem here

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0how do yo know its 270?

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0think of where 64i is in the complex plane. it is straight down 64 units, so trig form is what i wrote. you can also use \[64i=64e^{\frac{3\pi}{2}i}\] and do it that way

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0oh how to i know it is 270?

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0draw the complex plane and imagine where 64i is. it is straight down 64 units, think of it as \[064i\]

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0what math class is this? i never learned this stuff

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0you can do this as soon as you learn trig

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0write \[a+bi\] as \[r(\cos(\theta)+i\sin(\theta)\] where \[r=\sqrt{a^2+b^2}\] and \[\tan(\frac{b}{a})=\theta\]

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0in any case when you want the sixth roots, take the sixth root of the absolute value and divide the angle by 6

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0If\[w^{6} = 64 i,\]then\[w = \sqrt[6]{64}= 2.\]The angle \[\theta = 3 \pi/2,\]so one of the sixth roots of 64i will be a vertex of the regular hexagon lf side length 2 centered at z = 0, and making an angle \[\theta/6 = (3 \pi/2)/6 = \pi/4.\] That vertex is at\[z = 2 \cos(\pi/4) + 2i \sin(\pi/4) = \sqrt{2} + i \sqrt{2}.\]All the sixth roots are\[2 \cos(\pi/4 + k \pi/3) + 2i \sin(\pi/4 + k \pi / 3),\]where k is an integer.

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0so first answer is \[2(\cos(45)+i\sin(45)\] \[=2(\frac{\sqrt{2}}{2}+\frac{\sqrt{2}}{2}i)\] \[=\sqrt{2}+\sqrt{2}i\]

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0to get second answer just divide circle up into 6 equal parts with one part at 45 degrees. or go around the circle again and write \[64i=64(\cos(630)+i\sin(630))\] and now divide 630 by 6 to get 105 so second answer is \[2(\cos(105)+i\sin(105))\] etc

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0abtrehearn answer more elegant

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0how did you get that angle 3pi/2 when it looks like im meant to go tan 0/2

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0here is a picture of the unit circle in the complex plane. you can see that the angle associated with i is \[\frac{3\pi }{2}\]

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0and by the way it is \[\theta =\tan(\frac{b}{a})\] which is this case is \[\tan(\frac{64}{0})\] which is undefined

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0The angle\[3 \pi/2\]comes from plotting (0, 64) on the xy plane and measuring counterclockwise from the positive xaxis to the point. That's three right angles, or \[3 \pi/2\]radians.

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0no wonder the 6th root of it is pi/2?

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0if you want to do this the slow donkey way, which may not be a bad idea the first time you see it, start with 270 degrees (i know we really should work in radians but this will make my typing easier) then divide 270 by 6 for the next one add 360 to 270 to get 630, divide by 6 to get 105

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0then for the next one add 360 again to get 990 and divide by 6 to get 165 etc

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0around again you get 990+360=1350 divide by 6 to get 225 around again you get 1350+360=1710 divide by 6 get 285 around again you get 1710+360=2070 divide by 6 get 345 and finally around again you get 2070+360 = 2430 divide by 6 get 405 which is the same as 45 so you are back where you started

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0this is certainly not the elegant way to do it, but it gets the point across

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.045 + 60 = 105 105 + 60 = 165 165 + 60 = 225 225 + 60 = 285 285 + 60 = 345. Those are the angles for the vertices in degrees.
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