A boy walks 6 km from a point P to a point Q on a bearing of 065. He then walks to a point R at a distance of 13 km on a bearing
1 answer:
9514 1404 393
Answer:
- see below for a sketch
- 12 km
Step-by-step explanation:
The distance can be calculated using the Law of Cosines. The angle internal to the triangle at Q is (180°-(146° -65°)) = 99°. Then the distance PR can be found from ...
PR² = PQ² +QR² -2·PQ·QR·cos(∠PQR)
PR² = 6² +10² -2·6·10·cos(99°) ≈ 154.77
PR ≈ √154.77 ≈ 12.44 . . . . km
The distance PR is about 12 km.
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b: The y-intercept (The point where the line is at the y-axis)
Now that we've defined our variables, how do we go about making the actual equation? Let's start off with the slope, m.
The slope is a measure of how high or low the line is. The number is a ratio between the rise and run of a slope. In other words, it is essentially
Let's look back at the graph. In the time interval from 1 to 2 seconds, we see that the line rises by 22 feet. Because the time interval is only 1 second, the run is 1 second.
Therefore:
m =
m =
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We now have the first variable of the equation.
y = 22x + b
What about b? As we established earlier, b is the value of coordinate y at the y-intercept. Essentially, to find b we need to know what the value of y is when the coordinate x is 0.
As you can see from the graph you made, the value of y when x is 0 is also 0. This makes sense, too. How can the cheetah travel distance at 0 seconds when it obviously hasn't started moving? We now know b = 0. Now, we have gotten all of the variables we need to make a full equation:
y = 22x + 0
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If you'd like me to explain how I did anything, just ask!
- breezyツ