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
The equation which represent the problem is 14.5 = 469.8k.
<h3>What is Equation?</h3>
An equation is a mathematical statement with an 'equal to =' symbol between two expressions that have equal values.
Here, As given in question
The number of gallons of gas Connie’s car, g, uses is directly proportional with the number of miles she drives, m.
g α m
g = km ............(i)
g = 14.5 gallons of gas m = 469.8 miles
14.5 = k X 469.8
14.5 = 469.8k
Thus, the equation which represent the problem is 14.5 = 469.8k.
Learn more about Equation from:
brainly.com/question/2263981
#SPJ1
The question states that both parts of Noshi's desk were shaped like trapezoids and both had a height of 3.
We know that the formula for area of a trapezoid is (a+b)/2 * h, where a and b are bases of the trapezoid and h is the height. Note: This is like any other form of trying to find the area, because we are doing base times height, however, we need to divide the sum of the bases by 2 to find the average base length.
Let's call the first trapezoid on the left Trapezoid A and the second slanted trapezoid Trapezoid B.
Area of Trapezoid A = (a+b)/2 * h = (5+8)/2 * 3 = 13/2 * 3 = 6.5 * 3 = 19.5 feet
Area of Trapezoid B = (a+b)/2 * h = (4+9)/2 * 3 = 13/2 * 3 = 6.5 * 3 = 19.5 feet
To find the area of Noshi's total desk, we simply need to add the areas of Trapezoid A and Trapezoid B together.
19.5 feet + 19.5 feet = 39 feet
Therefore, the area of Noshi's desk is 39 feet.
Hope this helps! :)
Answer:3.1944
Step-by-step explanation:
(1÷1×3)+1÷(2×4)+1÷(3×5)+1÷(18×20)
