Question Number: 1
Find the value of 'y' if points A, B, and C are collinear: A(-3,-1), B (0.y), and C (3.-9).
Answers
Answered by
0
Answer:
Points are P(1,4),Q(3,y) and R(−3,16) are collinear.
Which means area of triangle PQR=0
Area of triangle =
2
1
[x
1
(y
2
−y
3
)+x
2
(y
3
−y
1
)+x
3
(y
1
−y
2
)]
=
2
1
[1(y−16)+3(16−4)+(−3)(4−y)]
=
2
1
[y−16+3×12−12+3y]
=
2
1
[4y−16+36−12]=
2
1
[4y+8]
Since points are collinear:
2
1
(4y+8)=0
or y=−2.
Answered by
0
Answer:
x1=-3
x2=0
X3=3
y1=-1
y2=y
y3=-9
For points to be collinear
x1(y2-y3)+x2(y3-y2)+x3(y1-y2)
-3(-1-(-9))+0(-9-y)+3(-1-y)=0
-3(-1+9)+0-3-3y=0
-3(8)-3-3y=0
-24-3-3y=0
-27-3y=0
-3y=27
y=-9
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