Question 65147:  The conjugate of  5 + 6i  is 
Find the product  (2 + i)(3 + 4i).   Give your answer in the usual   a + bi  form 
Write the complex number  i 15   in the usual   a + bi  form  
Find the reciprocal of the complex number   3 + 2i .    Give your answer in the usual  a + bi  form. 
 
Write the complex number in the usual a + bi form.  
What are the coordinates of the complex number   -i  when we plot it in the complex plane?  
 Find the magnitude of the complex number  3 - 7i.    (In other words, find  | 3 -  7i | )  
 Answer by stanbon(75887)      (Show Source): 
You can  put this solution on YOUR website! The conjugate of 5 + 6i is 5-6i 
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Find the product (2 + i)(3 + 4i). Give your answer in the usual a + bi form 
Use FOIL: 
F:2*3=6 
O:2*4i=8i 
I:3*i=3i 
L:i*4i=-4 
Combine to get:2+11i 
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Write the complex number i 15 in the usual a + bi form 
0+15i 
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Find the reciprocal of the complex number 3 + 2i . Give your answer in the usual a + bi form. 
1/(3+2i)=[3-2i)}/[3+2i)(3-2i)]=[ 3-2i]/[13]=(3/13)-(2/13)i 
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What are the coordinates of the complex number -i when we plot it in the complex plane?  
(0,-1) 
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Find the magnitude of the complex number 3 - 7i. (In other words, find | 3 - 7i | )  
|3-7i|=sqrt(9+49)=sqrt58 
Cheers, 
Stan H. 
 
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