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| Question 1180531:  Find the 3 cube roots of i in polar form.
 Found 2 solutions by  ikleyn, Edwin McCravy:
 Answer by ikleyn(52879)
      (Show Source): 
You can put this solution on YOUR website! . Find the 3 cube roots of i in polar form.
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    i = (1,  ) = (1,90°)  in polar form  (the modulus is 1;  the argument is  ,  or  90°).
Use deMoivre formula.  The three cubic roots of " i " are
a)  (1,  ) = (1,30°);
b)  (1,  ) = (1,  ) = (1,  ) = (1,150°);
c)  (1,  ) = (1,  ) = (1,  ) = (1,270°).
 Solved and explained.
 
 
 
Answer by Edwin McCravy(20064)
      (Show Source): 
You can put this solution on YOUR website! 
While correct, neither the notation (r,θ) nor rei*θ is used when teaching complex numbers 
in basic trigonometry courses.  That's because such notation eliminates the trigonometric functions.
Find the 3 cube roots of i in polar form. 
i = 0 + 1i
Graph the vector whose magnitude (modulus) is r=1, whose tail is at (0,0),
and whose tip is at (0,1), and whose argument (angle) is θ=90o. 
        Since the cube root is the 1/3 power:    We raise everything to the 1/3 power.  In doing so we will use deMoivre's
theorem, where we raise the magnitude (modulus 1) to the 1/3 power (i.e.,
take its cube root 1), and multiply its argument (angle) by 1/3.  Now, since there are 3 cube roots, we take three consecutive integers for n.
Let n=0    Let n=1    Let n=2      .
Edwin
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