9514 1404 393
Answer:
Step-by-step explanation:
The tangent of the angle can be found using the identity for the tangent of the difference of angles.
tan(α-β) = (tan(α) -tan(β))/(1 +tan(α)tan(β))
The tangent of the angle of each vector is the ratio of the j coefficient to the i coefficient.
tan(α) = -2/3
tan(β) = 4/7
tan(α-β) = (-2/3 -4/7)/(1 +(-2/3)(4/7))
= (-14-12)/(21 -8) = -26/13 = -2
Then the magnitude of the angle between the vectors is ...
arctan(2) ≈ 63.43°
Answer:
Property of Addition
Step-by-step explanation:
For all real numbers x, y, and z ,
if x = y, then x + z = y + z .
if a = 5, and 5 + z = 14, so a + z = 14
Let x represent lower level tickets that cost $77
Let y represent upper level tickets that cost $99
Cost equation: 77x + 99y = 247,071
Tickets equation: x + y = 2615
Using the elimination method, multiply the second equation by -77:
77x + 99y = 247,071
-77x - 77y = -201,355
--> 22y = 45,716
--> y = 2,078
Now plug "y" into either equation and solve for "x". I chose the Tickets equation. x + y = 2615 → x = 2615 - y → x = 2615 - 2078 → x = 537
Answer: lower level = 537 tickets, upper level = 2078 tickets.
Answer:
These two triangles are <em>similar triangles. </em>This means that their side lengths are proportional to each other.
Thus, making line segment EC equal to "x", and BC equal to "y" we can write:
8/y = 28/(10+y)
The next step is to get rid of the fractions, which can be done by cross multiplying.
So we have:
8(10+y) = 28(y)
After distribution and some simplification, you should get the value of y.
80+8y = 28y
80 = 20y
80/20 = 20y/20
4 = y
y = 4
Knowing that y = BC, and y = 4, it is clear that BC = 4.
Since BC = 4, one can use the Pythagorean Theorem to solve for segment EC.
Pythagorean Theorem: a^2 + b^2 = c^2, where a and b are the side lengths of a right triangle, and c is the hypotenuse (in other words the longest side)
In our case, a and b are 8 and 4 (the order doesn't really matter here).
So we have: 8^2 + 4^2 = c^2
64 + 16 = c^2
80 = c^2
c = sqrt 80
c = 4 sqrt 5
And we arrive at the answer- EC = 4 sqrt 5, making B the correct choice.
Hope this helps!
You should get 375 seconds which is 6 1/4 of a minute or 6 minutes and 15 seconds
