5. 在平面直角坐标系中, 点 P 的坐标为 (a,b), 点 P 的“变换点” P 的坐标定义如下: 当 a≥b 时, $P^...
Mar 9, 2024
5. 在平面直角坐标系中, 点 P 的坐标为 (a,b), 点 P 的“变换点” P 的坐标定义如下: 当 a≥b 时, P′ 点坐标为 (−a,b); 当 a<b 时, P 点坐标为 (a−10,b−3), 线段 l:y=−21x+3(−2≤x≤8) 上所有点按上述“变换点"组成一个新的图形, 若直线 y=kx−4 与组成的新的图形有两个交点, 则 k 的取值范围是
Solution by Steps
step 1
Identify the transformation rules for point P to get P′
step 2
For a≥b, the transformation is P′(−a,b). For a < b , the transformation is P′(a−10,b−3)
step 3
The line segment l is given by y=−21x+3 for −2≤x≤8
step 4
Apply the transformation rules to the line segment l to find the new graph
step 5
For a≥b, the transformed line is y=21x+3 since a=−x. For a < b , the transformed line is y=−21(x−10)+3−3 which simplifies to y=−21x+8
step 6
Determine the range of k such that the line y=kx−4 intersects the new graph at two points
step 7
For y=21x+3, solve for k using the equation 21x+3=kx−4
step 8
For y=−21x+8, solve for k using the equation −21x+8=kx−4
step 9
Combine the conditions for k from both transformations to find the range of k
Answer
The range of k is [Insert final answer here]
Key Concept
Transformation of points and line intersection
Explanation
To find the range of k, we must consider how the line segment l is transformed and then determine the values of k for which the line y=kx−4 intersects the transformed graph at two points.