Question
Mathematics Question on Complex Numbers and Quadratic Equations
If a+ib=c+id, then
A
a2+c2=0
B
b2+c2=0
C
b2+d2=0
D
a2+b2=c2+d2
Answer
a2+b2=c2+d2
Explanation
Solution
a+ib=c+id ∴∣a+ib∣=∣c+id∣ ⇒a2+b2=c2+d2
If a+ib=c+id, then
a2+c2=0
b2+c2=0
b2+d2=0
a2+b2=c2+d2
a2+b2=c2+d2
a+ib=c+id ∴∣a+ib∣=∣c+id∣ ⇒a2+b2=c2+d2