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1、y/毫安x/天某手机的电板剩余电量y毫安是使用天数x的一次函数.x和y关系如图 ：此种手机的电板最大带电 量是多少？1000毫安此种手机的每天的耗电量 是多少？200毫安k=y2-y1 x2-x1Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyrig
2、ht 2004-2011 Aspose Pty Ltd.二元一次方程与一次函数在一次函数在一次函数 y y=3=3- -x x的图象上的图象上点点( ( s , t s , t ) )x x = = s s y y = = t t方程方程 x x+ +y y=3 =3 的解的解二元一次方程二元一次方程 x x+ +y y=3 =3 可改写成可改写成一次函数一次函数y y=3=3- -x xEvaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created
3、with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.方程组的解是对应的两条直线的 交点坐标.两条直线的交点坐标是对应的 方程组的解.Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.
4、5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.将方程组中各方程化为y=kx+b的形式；画出各个一次函数的图象； 由交点坐标得出方程组的解 图象法解方程组的步骤：Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Prof
5、ile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.例 用图象法解方程组由得: x3 32 21 1-1-1-2-2y-2-22 2-1-10 01 13解：由得：取点(-2,0)，(0,1)作出直线 .取点(1,0)，(0,-2),作出直线观察图象得出交点为（2,2)P(2,2)x=2y=2二元一次方程组的解为:Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profi
6、le 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.解二元一次方程组的方法代 入 消 元 法加 减 消 元 法函数 图象 法 要强调的 是：由于 作图的不 准确性， 由图象法 求得的解 是近似解 .找两直线交点坐标的方法Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.
7、5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.方程组 解的情况如何？你能从函数角度解释一下吗？Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.S
8、lides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.O4312yx23451-1-2-4-3-4-3-2-1-5练习：P240 数学理解 65y=2-xy=5-x无解Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NE
9、T 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.两条直线互相平行，有 交点；0个Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspo
10、se Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.1、方程组 有 个解；2、方程组 有 个解；3、方程组 有 个解；0无数一从函数角度解释：Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004
11、-2011 Aspose Pty Ltd.两条直线重合，有 交点；无数个Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.1、方程组 有 个解；2、方程组 有 个解；3、方程组 有 个解；0
12、无数一从函数角度解释：Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.两条直线相交，有 交点；一个Evaluation only.Evaluation only. Created with
13、 Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.1、方程组 有 个解；2、方程组 有 个解；3、方程组 有 个解；0无数一从函数角度解释：Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3
14、.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.二元一次方程和一次函数（2） Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides fo
15、r .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.议一议：议一议：A A、B B 两地相距两地相距150150千米，甲、乙两人骑千米，甲、乙两人骑 自行车分别从自行车分别从A A、B B 两地两地相向相向而行。假设他而行。假设他 们都保持匀速行驶，则他们们都保持匀速行驶，则他们各自到各自到A A地的距地的距 离离 s s( (千米千米) )都是都是骑车时间骑车时间 t t ( (时时) )的一次函的一次函 数数. .1 1 时后乙距时后
