document.write( "Question 1201677: PLEASE do GIVE CoRRECT AnSwers\r
\n" ); document.write( "\n" ); document.write( "1. Convert the rectangular form of the complex number 2-2i
\n" ); document.write( " into polar form. Show all work and label the modulus and argument.\r
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\n" ); document.write( "\n" ); document.write( "2. Find all cube roots of the complex number 64(cos(219 degree) + i sin (219 degree)). Leave answers in polar form and show all work.
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Algebra.Com's Answer #836152 by math_tutor2020(3817)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "Edit: Sorry I had a brainfart. I mentioned the angle in Q2 when it should have been Q4.
\n" ); document.write( "I have fixed the mistake.\r
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\n" ); document.write( "\n" ); document.write( "I'll do problem 1 to get you started.\r
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\n" ); document.write( "\n" ); document.write( "2-2i = 2 + (-2)i
\n" ); document.write( "this is written in the form a+bi
\n" ); document.write( "a = 2
\n" ); document.write( "b = -2\r
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\n" ); document.write( "\n" ); document.write( "r = modulus
\n" ); document.write( "r = sqrt(a^2+b^2)
\n" ); document.write( "r = sqrt((2)^2+(-2)^2)
\n" ); document.write( "r = sqrt(4+4)
\n" ); document.write( "r = sqrt(8)
\n" ); document.write( "r = sqrt(4*2)
\n" ); document.write( "r = sqrt(4)*sqrt(2)
\n" ); document.write( "r = 2*sqrt(2)\r
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\n" ); document.write( "\n" ); document.write( "theta = argument
\n" ); document.write( "theta = arctan(b/a)
\n" ); document.write( "theta = arctan(-2/2)
\n" ); document.write( "theta = arctan(-1)
\n" ); document.write( "theta = -45°
\n" ); document.write( "Add 360 degrees to find a coterminal angle in the range 0 ≤ theta < 360
\n" ); document.write( "-45+360 = 315\r
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\n" ); document.write( "\n" ); document.write( "Summary:
\n" ); document.write( "r = 2*sqrt(2)
\n" ); document.write( "theta = 315°\r
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\n" ); document.write( "\n" ); document.write( "The polar point (r, theta) is (2*sqrt(2), 315°)\r
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\n" ); document.write( "\n" ); document.write( "Another way you could express the answer would be to say the following
\n" ); document.write( "z = r*( cos(theta) + i*sin(theta) )
\n" ); document.write( "z = 2*sqrt(2)*( cos(315°) + i*sin(315°) )
\n" ); document.write( "z = 2*sqrt(2)*cis(315°)
\n" ); document.write( "where \"cis\" is shorthand for \"cosine i sine\"
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