"Show that the sum of a+bi and its conjugate is a real number"
How???
2007-08-09 19:27:46 · 7 answers · asked by Katie M 2 in Science & Mathematics ➔ Mathematics
a and b are real numbers.
a+ bi is a complex number
The complex conjugate of a+ bi is a - bi.
a + bi + a - bi = 2a
Since a is a real number, 2a is also a real number because the Reals are closed under addition, a + a = 2a.
2007-08-09 19:30:43 · answer #1 · answered by David K 3 · 0⤊ 0⤋
conjugate is a-bi
a+bi +a-bi=2a which is a real number
2007-08-10 02:44:29 · answer #2 · answered by MathStudent 3 · 0⤊ 0⤋
conjugate of a+bi = a- bi
so: a+bi + a-bi = 2a (only the real number)
2007-08-10 02:33:39 · answer #3 · answered by Anonymous · 0⤊ 0⤋
a + bi
conjugate is a - bi
a + bi + a - bi
= 2a
which is a real number
.
2007-08-10 02:29:50 · answer #4 · answered by tsr21 6 · 1⤊ 0⤋
its conjugate is a-bi
therefore,
(a+bi) + (a-bi) = a+a+bi-bi = 2a
2a is real since (a) is real...
2007-08-10 02:30:38 · answer #5 · answered by Anonymous · 1⤊ 0⤋
given a +bi
conjugate of a +bi is a-bi
z=(a+bi)+(a-bi)=2a
2007-08-10 03:11:32 · answer #6 · answered by ptolemy862000 4 · 0⤊ 0⤋
(a + bi) + (a - bi)
= 2a + bi - bi
= 2a (which is a real number)
2007-08-10 02:32:26 · answer #7 · answered by Como 7 · 0⤊ 0⤋