(math)幫解函數問題國一

1.函數f(x)=(2k+6)x+m-7的圖形為通過(-4,-5)
//x軸: 2k + 6 = 0 ==> k = -3f(-4) = m - 7 = -5 ==> m = 2k + m = -3 + 2 = -1
2.線型函數f(x)的圖形通過點(k,3k-5),則f(-4)=?
f(x) = x + af(k) = k + a = 3k - 5 ==> a = 2k - 5f(-4) = x + 2k - 5= -4 + 2k - 5= 2k - 9

3.兩軸所圍成的三角形面積為18平方單位,則a的值為?
f(x) = -ax + 12f(0) = 120 = -ax + 12 ==> x = 12/aA = 18= 0.5 * 12 * 12/|a|= 72 / |a||a| = 72/18 = 4=> a = +-4

嗆得好
不是懶得讀書就是豬腦袋～