But you cant be fined $-10, so you would change the negative to a positive.
each truck payment was $10.
Verify that the points are the vertices of a parallelogram and find its area. (2,-1,1), (5, 1,4), (0,1,1), (3,3,4)
1 answer:
Answer:
Verified
Area = 13.12 square units.
Step-by-step explanation:
Let the given points / vertices of the parallelogram be represented as follows:
A(2,-1,1),
B(5, 1,4),
C(0,1,1),
D(3,3,4)
In vector notation, we can have;
A = 2i - j + k
B = 5i + j + 4k
C = 0i + j + k
D = 3i + 3j +4k
One of the ways to prove that a quadrilateral is a parallelogram is to show that both pairs of opposite sides are parallel.
(i) Now, let's find the various sides of the assumed parallelogram. These sides are:
AB = B - A = [5i + j + 4k] - [2i - j + k] <em>open the brackets</em>
AB = 5i + j + 4k - 2i + j - k <em>collect like terms and solve</em>
AB = 5i - 2i + j + j - k + 4k
AB = 3i + 2j+ 3k
BC = C - B = [0i + j + k] - [5i + j + 4k] <em>open the brackets</em>
BC = 0i + j + k - 5i - j - 4k <em>collect like terms and solve</em>
BC = 0i - 5i + j - j + k - 4k
BC = -5i + 0j - 3k
CD = D - C = [3i + 3j +4k] - [0i + j + k] <em>open the brackets</em>
CD = 3i + 3j + 4k - 0i - j - k <em>collect like terms and solve</em>
CD = 3i - 0i + 3j - j + 4k - k
CD = 3i + 2j + 3k
DA = A - D = [2i - j + k] - [3i + 3j +4k] <em>open the brackets</em>
DA = 2i - j + k - 3i - 3j - 4k <em>collect like terms and solve</em>
DA = 2i - 3i - j - 3j + k - 4k
DA = - i - 4j - 3k
AC = C - A = [0i + j + k] - [2i - j + k] <em>open the brackets</em>
AC = 0i + j + k - 2i + j - k <em>collect like terms and solve</em>
AC = 0i - 2i + j + j + k - k
AC = - 2i + 2j +0k
BD = D - B = [3i + 3j + 4k] - [5i + j + 4k] <em>open the brackets</em>
BD = 3i + 3j + 4k - 5i - j - 4k <em>collect like terms and solve</em>
BD = 3i - 5i + 3j - j + 4k - 4k
BD = - 2i + 2j + 0k
(ii) From the results in (i) above, it has been shown that;
AB is equal to CD, and that implies that AB is parallel to CD. i.e
AB = CD => AB || CD
<em>Also,</em>
AC is equal to BD, and that implies that AC is parallel to BD. i.e
AC = BD => AC || BD
(iii) Therefore, ABDC is a parallelogram since its opposite sides are equal and parallel.
(B) Now let's calculate the area of the parallelogram.
To calculate the area, we find the magnitude of the cross product between any two adjacent sides.
In this case, we choose sides AC and AB.
Area = | AC x AB |
Where;
AC X AB = i(6 - 0) - j(-6 - 0) + k(-4 -6)
AC X AB = 6i + 6j - 10k
|AC X AB| =
|AC X AB| =
|AC X AB| =
|AC X AB| = 13.12
Therefore the area is 13.12 square units.
PS: The diagram showing this parallelogram has been attached to this response.
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But you cant be fined $-10, so you would change the negative to a positive.
each truck payment was $10.
Conditional Probability
Given two events A and B (not excluding), the probability that A occurs given that B has occurred is called a <em>conditional probability</em> and is calculated as:
Where P(A∩B) is the probability that A and B occur simultaneously and P(B) is the probability that B occurs.
Now with the given data, we must find the values of the required probabilities.
30% of the students play a sport (S), this means that:
70% of the students don't play a sport (NS).
65% of the students have a job.
Note that there could be students who both play sports and have a job.
Of the 30% of the students who play a sport, 50% have a job. This means that:
15% of the students play a sport and don't have a job
15% of the students play a sport AND have a job
65% - 15% = 50% of the students have a job and don't play a sport
That last number is the numerator of the equation given above:
P(A∩B) = 0.5
The event B corresponds to students that don't play a sport (NS), thus:
P(B) = 0.7
Thus we have:
The required probability is 5/7 or 0.7143