Let f(x) = -x² + bx + c and g(x) = mx + c, where m > b.
If the graph of y = f(x) and the graph of y = g(x) intersect at 2 points A and B, find the distance between A and B
Distance
2015-03-21 8:14 pm
回答 (2)
2015-03-21 9:48 pm
✔ 最佳答案
Solving the two equations y = f(x) and y = g(x), we get,-x² + bx + c = mx + c==> x² + (m - b)x = 0==> x(x + m - b) = 0==> x = 0 or x = b - mWhen x = 0, y = m(0) + c = c ;When x = b - m, y = m(b - m) + c = -m² + bm + cSo, distance between AB is :√[(0 - b + m)² + (c + m² - bm - c)²]＝√[(m - b)² + m²(m - b)²]＝(m - b)√(1 + m²) (units)
2015-03-22 1:34 am
It may be another solution.
http://postimg.org/image/50w4d8r8t/
http://postimg.org/image/50w4d8r8t/
收錄日期: 2021-04-30 01:45:14
原文連結 [永久失效]:
https://hk.knowledge.yahoo.com/question/question?qid=7015032100035