Complex Number Equations

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Section 6.6

Can you do 91 and 93 as a guide for me to do a few more? Thank you.

Screenshot_20220225-174758_Samsung Notes.jpg
 
91
\(x^4+16i=0\)

\(x^4=-16i\)

MSP66112006977a75fh4g5200004h431iec4f095hha


MSP218016be747f34e5079200003haf1di7iaf219gg


solutions are:

\(x = 2cos(π/8) - 2i *sin(π/8)\)

\(x = 2cos(-π/8) + i *sin(-π/8)\)


93

\(x^3-(1-i)=0\)

\(x^3=(1-i)\)

MSP7039200696094h9gh336000012cdf13bbbiigi26


MSP118301dafi198caaib4b7000045f76d43ce2he3c5
 
Last edited:
91
\(x^4+16i=0\)

\(x^4=-16i\)

MSP66112006977a75fh4g5200004h431iec4f095hha

Very cool. Maybe I will try a few when time allows.
Feeling discouraged. Went through this section TWICE and just not picking up the material. Bad sign for calculus.

How did you get from x = 4throot {-16i} to x = 2•4throor{-i}?

How did you get from x = cuberoor{1 - i} to the final answer for x?


MSP218016be747f34e5079200003haf1di7iaf219gg


solutions are:

\(x = 2cos(π/8) - 2i *sin(π/8)\)

\(x = 2cos(-π/8) + i *sin(-π/8)\)


93

\(x^3-(1-i)=0\)

\(x^3=(1-i)\)

MSP7039200696094h9gh336000012cdf13bbbiigi26


MSP118301dafi198caaib4b7000045f76d43ce2he3c5
 
91
\(x^4+16i=0\)

\(x^4=-16i\)

MSP66112006977a75fh4g5200004h431iec4f095hha


MSP218016be747f34e5079200003haf1di7iaf219gg


solutions are:

\(x = 2cos(π/8) - 2i *sin(π/8)\)

\(x = 2cos(-π/8) + i *sin(-π/8)\)


93

\(x^3-(1-i)=0\)

\(x^3=(1-i)\)

MSP7039200696094h9gh336000012cdf13bbbiigi26


MSP118301dafi198caaib4b7000045f76d43ce2he3c5

IMG_20220227_190446.jpg


IMG_20220227_190453.jpg


For 92 and 94, I need a step by step solution starting where I got stuck. Thank you. This completes Chapter 6 for us. I was going to skip Chapters 7 through 9 but decided that this is a bad idea. Chapter 7 begins next Friday. Back to work tomorrow. My weekend is over.

IMG_20220227_190509.jpg


IMG_20220227_190520.jpg
 
88.
from here
MSP75062006e388829048d00000460470d648i0a994


MSP14570125ia3d970cea343000065i487h9530ibgab


90.
MSP1021cf98c28e9i41ge90000137h1a3c0b6386ag

that is real solution, but we also have two complex solutions

MSP115941c489f96gbh9f6ad000059h84562iiabiab6

MSP1211998f5235iaedg6d00000dh68dc39g8i7108


92.
x^6+64*i=0
x^6= -64*i

For z^n=a the solutions are :

MSP3130125iaeabci3199g900004850b5ga8eh6912c


k=0,1,..... ,n-1
for n=6, a=-64i

substituting values for a, n, and k you will get following complex solutions:

MSP121623a5i02d7e1gc48600006076664570i1701h


MSP121823a5i02d7e1gc486000056i93669icf98714


MSP122023a5i02d7e1gc486000058d4d4beaieb3d5i


MSP122223a5i02d7e1gc48600001bghhi8263h3h829


MSP122423a5i02d7e1gc486000039a0icb9ch9b8620



94. doing this one using same method as in 92, solutions will be

MSP68431434a9g0eha0fd240000371a247h71d77436

MSP68451434a9g0eha0fd24000015fa0c5ccgfg7602

MSP68471434a9g0eha0fd2400000d17ig6ef49eieh3


MSP68491434a9g0eha0fd2400004a093cf14ab25e1c
 
88.
from here
MSP75062006e388829048d00000460470d648i0a994


MSP14570125ia3d970cea343000065i487h9530ibgab


90.
MSP1021cf98c28e9i41ge90000137h1a3c0b6386ag

that is real solution, but we also have two complex solutions

MSP115941c489f96gbh9f6ad000059h84562iiabiab6

MSP1211998f5235iaedg6d00000dh68dc39g8i7108


92.
x^6+64*i=0
x^6= -64*i

For z^n=a the solutions are :

MSP3130125iaeabci3199g900004850b5ga8eh6912c


k=0,1,..... ,n-1
for n=6, a=-64i

substituting values for a, n, and k you will get following complex solutions:

MSP121623a5i02d7e1gc48600006076664570i1701h


MSP121823a5i02d7e1gc486000056i93669icf98714


MSP122023a5i02d7e1gc486000058d4d4beaieb3d5i


MSP122223a5i02d7e1gc48600001bghhi8263h3h829


MSP122423a5i02d7e1gc486000039a0icb9ch9b8620



94. doing this one using same method as in 92, solutions will be

MSP68431434a9g0eha0fd240000371a247h71d77436

MSP68451434a9g0eha0fd24000015fa0c5ccgfg7602

MSP68471434a9g0eha0fd2400000d17ig6ef49eieh3


MSP68491434a9g0eha0fd2400004a093cf14ab25e1c

I don't understand this complex equation stuff. I never studied this material back in my college days. Looks terribly advanced for precalculus students. What is the name of the course that goes into great detail concerning such equations? I took precalculus back in 1993. The professor did not teach this stuff.
 

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