Eric Nicholas K's answer to lim's Junior College 2 H3 Maths Singapore question.

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Eric Nicholas K
Eric Nicholas K's answer
5997 answers (Tutor Details)
1st
I am only capable of doing this one part. Forgot my complex numbers fully.
lim
Lim
4 years ago
thanks for yout hard effort,really appreciate
J
J
4 years ago
Shorter alternative:

a² + b² + c² = bc + ca + ab

(-4 + 4i)² + (4 - 2i)² + c² = (4 - 2i)c + c(-4 + 4i) + (-4 + 4i)(4 - 2i)

16 - 32i - 16 + 16 - 16i - 4 + c² = c(4 - 2i - 4 + 4i) - 16 + 8i + 16i + 8

12 - 48i + c² = 2ci - 8 + 24i

c² - 2ci - 1 = 72i - 21

c² - 2ci + i² = 3(9 - 24i - 16)

(c - i)² = 3(3² - 2(3)(4i) + (4i)²)

(c - i)² = 3(3 + 4i)²

k = 3
lim
Lim
4 years ago
thanks for your alternative method
J
J
4 years ago
Welcome. Do take note of the need to reject the value of c with both real and imaginary part negative in the last part
lim
Lim
4 years ago
deeply appreciate