Answer: Choice D)
The angle between the two vectors is approximately 71.6 degrees
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Work Shown:
Each time I write the word "dot" I mean "dot product".
|u| = length of vector u
|u| = sqrt(u dot u)
|u| = sqrt(<8,4> dot <8,4>)
|u| = sqrt(8*8 + 4*4)
|u| = sqrt(64 + 16)
|u| = sqrt(80)
|u| = sqrt(16*5)
|u| = sqrt(16)*sqrt(5)
|u| = 4*sqrt(5)
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|v| = length of vector v
|v| = sqrt(v dot v)
|v| = sqrt(<9,-9> dot <9,-9>)
|v| = sqrt(9*9 + (-9)*(-9))
|v| = sqrt(81+81)
|v| = sqrt(2*81)
|v| = sqrt(2)*sqrt(81)
|v| = sqrt(2)*9
|v| = 9*sqrt(2)
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u dot v = <8,4> dot <9,-9>
u dot v = 8*9 + 4*(-9)
u dot v = 72-36
u dot v = 36
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cos(theta) = (u dot v)/(|u|*|v|)
cos(theta) = (36)/(4*sqrt(5)*9*sqrt(2))
cos(theta) = (36)/(36*sqrt(10))
cos(theta) = 1/(sqrt(10))
cos(theta) = sqrt(10)/10
theta = arccos(sqrt(10)/10)
theta = 71.56505
which rounds to 71.6 when rounding to one decimal place (nearest tenth)
That's why the approximate answer is roughly 71.6 degrees
An example of a direct variation scenario is the increase in the income of a start-up bakeshop when the number of cakes sold increase. Example data are (4, $ 100), (5, $ 125), (6, $ 150), and (7, $ 175).
The example of indirect variation scenario is the decrease in time it takes to reach a destination when the speed of the mobile increases. This is shown in the data points: (10 kph, 10 mins), (12 kph, 8 mins), (14 kph, 6 mins), and (16 kph, 4 mins).
Answer: 78
Step-by-step explanation: typed it into a calculator
Answer:
(2x+1)(x+7)
Step-by-step explanation:
2x2+15x+7
For a polynomial of the form ax2+bx+c
, rewrite the middle term as a sum of two terms whose product is a⋅c=2⋅7=14 and whose sum is b=15
.
Tap for more steps...
2x2+x+14x+7
Factor out the greatest common factor from each group.
Tap for more steps...
x(2x+1)+7(2x+1)
Factor the polynomial by factoring out the greatest common factor, 2x+1
.
(2x+1)(x+7)
