[size=150]실수의 제곱은 [math]\large 0[/math] 또는 양의 실수이므로 실수는 이차방정식 [math]\large x^2=-1[/math]의 해가 될 수 없다. 따라서 이 방정식의 해가 존재하도록 하려면 실수가 아닌 새로운 수를 생각해야 한다. [br][br]제곱하여 [math]\large -1[/math]이 되는 새로운 수를 생각하고 이것을 기호 [math]\large \textcolor{#980000}\bold{i}[/math]로 나타낸다. 즉, [br][center][math]\large i^2=-1[/math][/center]이다. 이러한 수 [math]\large i[/math]를 [b][color=#980000]허수단위[/color][/b]라 하고, [math]\large i=\sqrt{-1}[/math]로 나타내기도 한다.[br][br]두 실수 [math]\large a[/math], [math]\large b[/math]에 대하여[br][center][math]\large\textcolor{#980000}\bold{a+bi}[/math][/center]꼴로 나타내어지는 수를 [b][color=#980000]복소수[/color][/b]라 하고, [math]\large a[/math]를 이 복소수의 [b][color=#980000]실수부분[/color][/b], [math]\large b[/math]를 이 복소수의 [b][color=#980000]허수부분[/color][/b]이라고 한다.[br]한편 [math]\large 0i=0[/math]로 정하면 실수 [math]\large a[/math]는[br][center][math]\large a=a+0i[/math][/center]로 나타낼 수 있으므로 실수도 복소수이다.[br]또 실수가 아닌 복소수 [math]\large a+bi \left( b \neq 0 \right)[/math]를 [b][color=#980000]허수[/color][/b]라고 한다.[br][br]두 복소수에서 실수부분은 실수부분끼리, 허수부분은 허수부분끼리 각각 같을 때, 두 복소수는 서로 같다고 한다. 특히 [math]\large a[/math], [math]\large b[/math]가 실수일 때, [math]\large a+bi=0[/math]이면 [math]\large a=b=0[/math]이다.[/size]

[size=150]실수를 수직선 위의 점과 대응시켜 나타낼 수 있는 것처럼 복소수를 좌표평면 위의 점과 대응시켜 나타내어 보자.[br]복소수 [math]\large z=a+bi[/math]([math]\large a[/math], [math]\large b[/math]는 실수)를 좌표평면 위의 점 [math]\large \rm{P}\left(a,b\right)[/math]에 대응시키면 이 점은 꼭 하나 정해지고, 역으로 좌표평면 위의 점 [math]\large \rm{P}\left(a,b\right)[/math]에 대하여 꼭 하나의 복소수 [math]\large z=a+bi[/math]가 정해진다. 즉 복소수 전체의 집합과 좌표평면 위의 점 전체의 집합은 일대일대응 관계를 이룬다. [br][/size][center][img]data:image/png;base64,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[/img][/center][size=150]아래 지오지브라 애플릿의 입력 부분(+ 표시 옆 칸)에 다음과 같이 입력하여 세 복소수 [math]\large 1-2i[/math], [math]\large 5[/math], [math]\large 3i[/math]를 복소평면에 나타내어 보자.[br][center][code]1-2i[/code][br][code]5+0i[/code][br][code]3i[/code][/center][/size][size=150]이와 같이 복소수를 대응시킨 평면을 [b][color=#980000]복소평면[/color][/b]이라 하고, 복소수 [math]\large z=a+bi[/math]를 나타내는 점을 기호로 [br][center][math]\large {\rm{P}}\left(a,b\right)[/math], [math]\large z[/math] 또는 [math]\large {\rm{P}}\left( z\right)[/math][/center]와 같이 나타낸다.[/size]

[size=150]직접 복소수를 입력하지 않고, [icon]/images/ggb/toolbar/mode_complexnumber.png[/icon] [b]복소수[/b] 도구를 이용하여 좌표평면 위의 특정 위치를 클릭하면 클릭한 점에 대응하는 복소수를 만들 수 있다. 복소수 도구를 이용하여 여러 복소수를 만들어보자.[/size]

[size=150]두 실수 [math]\large a[/math], [math]\large b[/math]에 대하여 복소수 [math]\large z=a+bi[/math]의 실수부분과 허수부분은 다음과 같이 기호로 나타낸다.[br][center][math]\large {\rm{Re}}\left(z\right)=a[/math], [math]\large {\rm{Im}}\left(z\right)=b[/math][/center][br]또, 복소평면 위에서 실수 [math]\large a=a+0i[/math]는 [math]\large x[/math]축 위의 점 [math]\large \left(a,0\right)[/math]으로, 순허수 [math]\large bi=0+bi[/math]는 [math]\large y[/math]축 위의 점 [math]\large \left(0,b\right)[/math]로 나타낼 수 있으므로, [math]\large x[/math]축을 [b][color=#980000]실수축[/color][/b], [math]\large y[/math]축을 [color=#980000][b]허수축[/b][/color]이라 한다.[/size]