A. Is (- 10, 21) a solution of y = - 3x - 9? b. Is (6, - 27) a solution of y= - 3x-9?
1 answer:
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Answer:
5 or less
Step-by-step explanation:
The speed increased linearly with distance, but is not decreasing linearly with distance. This suggests the track has an unknown shape, so prediction of car behavior is a guess, at best.
If the car continues to decrease its speed at 3 units per unit distance, then the final 3 units of speed will decrease to 0 in one additional unit of distance. That is, the car will stop at a distance of 5 units.
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Since the car has be decreasing its speed at an increasing rate with respect to distance, very possibly the car will stop before it reaches distance unit 5.
Since we don't know the track shape, it seems possible the car may not stop until some large unknown number of distance units, say 10 or 1000.
Answer:
A. -2sin(x)sin(0.4x)
Step-by-step explanation:
At x=0, the given expression evaluates to zero.
For x near zero, the given expression is slightly negative. You know this because cos(1.4x) decreases faster than cos(0.6x), so their difference will be negative.
Of the answer choices, you can eliminate C and D because they are not zero at x=0. You can eliminate choice B, because it is positive for values of x near zero. The only viable choice is A:
-2sin(x)sin(0.4x)
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Of course, a graphing calculator can help you figure this out. See the attachment. The given expression is plotted using a solid red line; the answer choice A is plotted using blue dots.
