A...maths Q~~~thz for yr help~~~urgent~~~－zogfly3的部落格

標題:

A...maths Q~~~thz for yr help~~~urgent~~~

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發問:

Draw the graph of y = |x^2 + 4x -1| from x = - 6 to x = 2. (((if u cannot draw the graph on this site,,, u can only type the first step of this Q))) thz a lot!!

最佳解答:

你代入x是-6 ,-5,-4 ....至到 2 然後睇返y是幾多咁就可以根據個資料畫圖但要注意係個圖y只可以係整數 so 要將y係負數果d反射上去正數果邊 (係指個圖) 咁就可以畫個圖啦

其他解答:

這些數據我是利用 Excel 產生出來。 Excel 中 y = |x^2 + 4x -1|所用的公式是 =abs(貯存格^2 + 4*貯存格 - 1) 例如 =ABS(A3^2+4*A3-1) 你可用 Excel 代你繪，或用下列的數據你自行繪出圖像 y = |x^2 + 4x -1| x y -6.00 11.00 -5.95 10.60 -5.90 10.21 -5.85 9.82 -5.80 9.44 -5.75 9.06 -5.70 8.69 -5.65 8.32 -5.60 7.96 -5.55 7.60 -5.50 7.25 -5.45 6.90 -5.40 6.56 -5.35 6.22 -5.30 5.89 -5.25 5.56 -5.20 5.24 -5.15 4.92 -5.10 4.61 -5.05 4.30 -5.00 4.00 -4.95 3.70 -4.90 3.41 -4.85 3.12 -4.80 2.84 -4.75 2.56 -4.70 2.29 -4.65 2.02 -4.60 1.76 -4.55 1.50 -4.50 1.25 -4.45 1.00 -4.40 0.76 -4.35 0.52 -4.30 0.29 -4.25 0.06 -4.20 0.16 -4.15 0.38 -4.10 0.59 -4.05 0.80 -4.00 1.00 -3.95 1.20 -3.90 1.39 -3.85 1.58 -3.80 1.76 -3.75 1.94 -3.70 2.11 -3.65 2.28 -3.60 2.44 -3.55 2.60 -3.50 2.75 -3.45 2.90 -3.40 3.04 -3.35 3.18 -3.30 3.31 -3.25 3.44 -3.20 3.56 -3.15 3.68 -3.10 3.79 -3.05 3.90 -3.00 4.00 -2.95 4.10 -2.90 4.19 -2.85 4.28 -2.80 4.36 -2.75 4.44 -2.70 4.51 -2.65 4.58 -2.60 4.64 -2.55 4.70 -2.50 4.75 -2.45 4.80 -2.40 4.84 -2.35 4.88 -2.30 4.91 -2.25 4.94 -2.20 4.96 -2.15 4.98 -2.10 4.99 -2.05 5.00 -2.00 5.00 -1.95 5.00 -1.90 4.99 -1.85 4.98 -1.80 4.96 -1.75 4.94 -1.70 4.91 -1.65 4.88 -1.60 4.84 -1.55 4.80 -1.50 4.75 -1.45 4.70 -1.40 4.64 -1.35 4.58 -1.30 4.51 -1.25 4.44 -1.20 4.36 -1.15 4.28 -1.10 4.19 -1.05 4.10 -1.00 4.00 -0.95 3.90 -0.90 3.79 -0.85 3.68 -0.80 3.56 -0.75 3.44 -0.70 3.31 -0.65 3.18 -0.60 3.04 -0.55 2.90 -0.50 2.75 -0.45 2.60 -0.40 2.44 -0.35 2.28 -0.30 2.11 -0.25 1.94 -0.20 1.76 -0.15 1.58 -0.10 1.39 -0.05 1.20 0.00 1.00 0.05 0.80 0.10 0.59 0.15 0.38 0.20 0.16 0.25 0.06 0.30 0.29 0.35 0.52 0.40 0.76 0.45 1.00 0.50 1.25 0.55 1.50 0.60 1.76 0.65 2.02 0.70 2.29 0.75 2.56 0.80 2.84 0.85 3.12 0.90 3.41 0.95 3.70 1.00 4.00 1.05 4.30 1.10 4.61 1.15 4.92|||||Determine y = 0 and y = |x^2+4x-1| 0 = |x^2+4x-1| 0 = x^2+4x-1 0 = (x+2)^2 - 5 x = -2 + sq root 5, or x = -2 -sq root 5 When x is less than -2 - sq root 5 or x is greater than -2 -sq root 5, y = |x^2+4x-1| = x^2+4x-1 is greater than zero. When x is between -2 - sq root 5 and -2 -sq root 5, x^2+4x-1 is less than zero. y = |x^2+4x-1| = -(x^2+4x-1) is greater than zero.