方程(1+i)x^2-(1-i)x-(2+6i)=0的實(shí)數(shù)解是?過程~~~謝謝~~~~~~~
熱心網(wǎng)友
(1+i)x^2-(1-i)x-(2+6i)=0---(x^2-x-2)+i(x^2+x-6)=0因?yàn)閤是實(shí)數(shù),所以x^2-x02;x^2+x-6分別是復(fù)數(shù)的實(shí)部和虛部。復(fù)數(shù)等于0的充要條件是實(shí)部和虛部都是0,所以x^2-x-2=(x-2)(x+1)=0---x=2;x=-1x^2+x-6=(x-2)(x+3)=0---x=2;x=-3顯然只有x=2使復(fù)數(shù)的實(shí)部和虛部都是0,所以原方程的實(shí)數(shù)解是x=2。
熱心網(wǎng)友
因(1+i)x^2-(1-i)x-(2+6i)=0(x^2-x-2)+(x^2+x-6)i=0所以x^2-x-2=0,== (x-2)(x+1)=0, == x=2,x=-1x^2+x-6=0, == (x+3)(x-2)=0, == x=2,x=-3既實(shí)數(shù)解是: x=-3,x=-1,x=2