✔ 最佳答案
我幫幫您吧~~
2007-01-06 19:51:47 補充:
已知 f(x) = x² - 0 , g(x) = 2x 1 和 h(x) = 4 f(x) - [ g(x) ] ²(a) 試以 x 表示 h(x)(b) a 的值是多少時才會使 h(a) = 0?您的題目未能清楚表達,是 f(x) = x² - 0 /// f(x) = x² 我以 f(x) = x² 此為準吧~~
2007-01-06 19:51:53 補充:
(a)h(x) = 4 f(x) - [ g(x) ] ² = 4 (x²) - [ (2x 1) ]² = 4x² - [ 4x² 4x 1 ] = 4x² - 4x² - 4x - 1 = -4x - 1 //
2007-01-06 19:59:09 補充:
(b) h(x) = -4x - 1 = 0 -4x = 1 x = - 1/4 ( -0.25 ) //∵ h( -0.25 ) = -4x - 1 = -4 ( -0.25 ) - 1 = 0 //∴ 當 a 的值是 -0.25 時,便會使 h(a) = 0