Find an equation of the plane that contains the points p(5,−1,1),q(9,1,5),and r(8,−6,0)p(5,−1,1),q(9,1,5),and r(8,−6,0).
topjm [15]
Given plane passes through:
p(5,-1,1), q(9,1,5), r(8,-6,0)
We need to find a plane that is parallel to the plane through all three points, we form the vectors of any two sides of the triangle pqr:
pq=p-q=<5-9,-1-1,1-5>=<-4,-2,-4>
pr=p-r=<5-8,-1-6,1-0>=<-3,5,1>
The vector product pq x pr gives a vector perpendicular to both pq and pr. This vector is the normal vector of a plane passing through all three points
pq x pr
=
i j k
-4 -2 -4
-3 5 1
=<-2+20,12+4,-20-6>
=<18,16,-26>
Since the length of the normal vector does not change the direction, we simplify the normal vector as
N = <9,8,-13>
The required plane must pass through all three points.
We know that the normal vector is perpendicular to the plane through the three points, so we just need to make sure the plane passes through one of the three points, say q(9,1,5).
The equation of the required plane is therefore
Π : 9(x-9)+8(y-1)-13(z-5)=0
expand and simplify, we get the equation
Π : 9x+8y-13z=24
Check to see that the plane passes through all three points:
at p: 9(5)+8(-1)-13(1)=45-8-13=24
at q: 9(9)+8(1)-13(5)=81+9-65=24
at r: 9(8)+8(-6)-13(0)=72-48-0=24
So plane passes through all three points, as required.
2x + y = 5
Put the coordinates of the points to the equation and check it:
A. 5 - not make sense
B. (1, 2) - x = 1, y = 2
2(1) + 2 = 2 + 2 = 4 ≠ 5 NOT
C. (2, -1) - x = 2, y = -1
2(2) + (-1) = 4 - 1 = 2 ≠ 5 NOT
D. (3, -1) - x = 3, y = -1
2(3) + (-1) = 6 - 1 = 5 YES
<h3>Answer: D. (3, -1).</h3>
The Cost of installing the artificial soccer pitch is $5360
A rectangle is a quadrilateral (has four sides and four angles) in which opposite sides are parallel and equal.
The soccer pitch us rectangle in shape. Hence:
Perimeter of soccer pitch = 2(length + width) = 2(91 + 43) = 268 meters
Cost of installing the pitch = $20 per meter * 268 meters = $5360
The Cost of installing the artificial soccer pitch is $5360
Find out more on perimeter at: brainly.com/question/16596982
Answer:
I think it is 9
Step-by-step explanation:
3×3 is 9 + 15= 24÷4=3×3=9
