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Answer: </h3><h3>
speed of train A = 44 mph</h3>
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Work Shown:
x = speed of train A
y = speed of train B
"train A travels 4/5 the speed of train B" (I'm assuming "train one" is supposed to read "train B"). So this means x = (4/5)y
distance = rate*time
d = x*7
d = (4/5)y*7 = (28/5)y represents the distance train A travels
d = y*7 = 7y represents the distance train B travels
summing those distances will give us 693
(28/5)y + 7y = 693
5*( (28/5)y + 7y ) = 5*693
28y + 35y = 3465
63y = 3465
y = 3465/63
y = 55
Train B's speed is 55 mph
4/5 of that is (4/5)y = (4/5)*55 = 4*11 = 44 mph
Train A's speed is 44 mph
solve for y
2x−4y=10
-2x -2x subtract -2x from both sides
-4y = -2x +10
-4 -4 Divide both sides by -4 (coefficient on y)
y = -2/-4x + 10/-4
y = 1/2x - 5/2
the slope is the number on the x (coefficient)
and its 1/2
Answer:
x= 21
y= 3
z= 21
Step-by-step explanation:
Let the center be O,
=> Triangle AOD is an Isosceles triangle so AO≅DO, "21 = x"
=> Line AC is divided in two equal parts by the center so if AO= 21 then
7y = 21, and thus "y = 3"
=> BOC is also an Isosceles triangle so CO ≅ BO, if CO = 21 (7y → 7*3) then so will be BO. Therefore "z = 21"
Answer:
is an even function.
Step-by-step explanation:
Recall when it means when a function is even or odd. An even function has the following property:
And an odd function has the following property:
So, let's test some values for cos(x).
Let's use π/3:
From the unit circle, was can see that this is 1/2 (refer to the x-coordinate).
Now, let's find -π/3. This is the same as 5π/3. Thus:
And again from the unit circle, we can see that this is 1/2.
Therefore, despite the negative, the function outputs the same value.
Cosine is an even function.
Notes:
Cosine is an even function and sine is an odd function. It's helpful to remember these as they can help you solve some trig problems!
