极值法又称为极端假设法,在数学教学里面是很有效的解题方法,将数学解题思想运用到物理的解题过程中,可以使物理解题变得更加简单快捷,简化了解题过程,使解题思路变得更加清晰,为考试赢得了时间.例1如图1甲所示的电路,电源电压保持不变.闭合开关S,调节滑动变阻器,两电压表的示数随电路中电流变化的图线 Extreme method, also known as the extreme hypothesis, which is a very effective method of solving problems in mathematics teaching. Applying the idea of ​​mathematical problem solving to the problem solving process of physics can make the problem of physics easier, quicker and easier to understand Problem process, the problem-solving ideas become clearer, won the time for the exam.Example 1 A circuit shown in Figure 1, the power supply voltage remains unchanged.Closed switch S, adjust the sliding rheostat, the number of the two voltmeter with Circuit diagram of current changes