The perpendicular distance from the point A(0,-2) to a line passing through the point of intersection of the lines 3x+4y-12 = 0 and 3x+y = 0 is sqrt(10). Find the possible equations of the line.
ans((step 1)):
Let the equation of the required line be
3x + 4y - 12 + k(3x+y) = 0
我想問下點解條 required line 唔可以係:
3x + y + k(3x+4y-12) = 0
我想知做尼種family of straight line題目時,,其實係點樣分辨邊條line擺先,,邊條line擺係 k 後面??
thanks for your help~
更新1:
假如照你所講個放係ｋ入邊都冇乜所謂... 咁我上述嘅example 3x + y + k(3x+4y-12) = 0 應該係啱啦?! 但係我點解計唔到個正確答案嘅?? thz~
