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一、展示不同解题方法,体现合作学习的魅力一次考试,同一道题目,可能出现多种不同解法,在试卷讲评中,让学生把各种不同解法充分展示出来,对开拓学生思维,有着很好的引导作用.考题:已知x2+y2=100,求x+y的最值.此题不难,但解决方法有多种,考试过后,同学们给出了多种不同解答.学生1:换元法,设x=10cosθ,y=10sinθ则x+y=10(cosθ+sinθ)=槡10 2 sin(θ+24),显然,最大值是槡10 2,最小值是-槡10 2.学生2:数形结合法,设t=x+y,则y=-x+t.转化为求直线y=-x+t截距的最大最小值,利用圆心到
First, to show different ways to solve problems, reflecting the attractiveness of cooperative learning test, the same topic, there may be a variety of different solutions, in the papers commentaries, so that students can fully demonstrate the different solutions, to develop students thinking, has a very Good guide. Test Questions: Known x2 + y2 = 100, seeking the best value of x + y. This problem is not difficult, but there are many solutions, after the exam, the students gave a variety of different answers. : Substitution method, if x = 10cosθ, y = 10sinθ then x + y = 10 (cosθ + sinθ) = 槡 10 2 sin (θ + 24). Obviously, the maximum value is 槡 10 2 and the minimum value is 槡 10 2. Student 2: Number combination method, set t = x + y, then y = -x + t. Converted to seeking straight line y = -x + t intercept of the maximum and minimum,