1试题呈现已知点P(1-2m,m-1),则不论m取什么值,该P点必不在()。A.第一象限B.第二象限C.第三象限D.第四象限2解法展示第一类解法:根据横、纵坐标符号特征,分类讨论求解。根据每个象限所在点坐标的符号规律进行求解。只要知道横、纵坐标的正负情况,就能确定P点所在的象限。因为m不确定,所以可先求出零点,然后根据m的不同取值范围,利用分类讨论进行求解。也 1 questions presented point P (1-2m, m-1), then no matter what value of m, the P-point will not be (). A. The first quadrant B. The second quadrant C. The third quadrant D. The fourth quadrant 2 Solution Show the first type of solution: According to the horizontal and vertical symbolic features, classification discussed to solve. According to each quadrant where the coordinates of the symbolic law to solve. Just know the horizontal and vertical coordinates of the positive and negative conditions, we can determine the P point where the quadrant. Because m is uncertain, we can find the zero point first, and then use the classification discussion to solve it according to the different value range of m. and also