1.P(-4,-3n/2), Q(-m-1,-3) and R(3m+2,n/2) are three points on a rectangular coordinate plane. Find m and n if (a) PQ is paralled to the y-axis and anglePQR = 90 degree, (b) PR is paralled to the y-axis (point P is above point R) and the distance between P and R is 12 units.
2. What is 'gas pressure' and 'density'?(Plx use Chinese to explain this question)
Thx!!
Questions
2007-05-30 3:39 am
回答 (1)
2007-05-30 5:23 am
✔ 最佳答案
1a)PQ is paralled to the y-axis
x-coord. of P = x-coord. of Q = -4
-m - 1 = -4
m = 3
anglePQR = 90
QR is paralled to the x-axis
y-coord. of R = y-coord. of Q = -3
n/2 = -3
n = -6
1b)
PR is paralled to the y-axis
x-coord. of P = x-coord. of R = -4
3m + 2 = -4
m = -2
distance between P and R = -3n/2 - n/2 = 12 ------------ (point P is above point R)
n = -6
2)
'gas pressure' = 氣壓
density = 密度
收錄日期: 2021-04-13 00:32:46
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