Write an expression that is equivalent to 8(2y+4)
1 answer:
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Answer:
y = 5cos(πx/4) +11
Step-by-step explanation:
The radius is 5 ft, so that will be the multiplier of the trig function.
The car starts at the top of the wheel, so the appropriate trig function is cosine, which is 1 (its maximum value) when its argument is zero.
The period is 8 seconds, so the argument of the cosine function will be 2π(x/8) = πx/4. This changes by 2π when x changes by 8.
The centerline of the wheel is the sum of the minimum and the radius, so is 6+5 = 11 ft. This is the offset of the scaled cosine function.
Putting that all together, you get
... y = 5cos(π/4x) + 11
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The answer selections don't seem to consistently identify the argument of the trig function properly. We assume that π/4(x) means (πx/4), where this product is the argument of the trig function.
Answer:
speed = (3/8 mi)/(3/5 h)
Step-by-step explanation:
... speed = distance/time
Fill in the given values:
... speed = (3/8 mi)/(3/5 h)
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<em>Comment on units</em>
You can use the units to provide both guidance and assurance. You know speed is generally expressed in <em>miles per hour</em>. If you consider "per" to mean "divided by", this expression of units tells you speed is calculated by dividing miles by hours.
If you leave the units with the numbers, as we have above, they enter into the calculation the same way any variable might. You can do the arithemetic with the numbers, and you can indicate the arithmetic with the units (just as you would with any variables). Here, the result of evaluating the equation would be ...
The fact that the units come out mi/h (the units of speed) provides assurance that you probably did the math correctly.