Answer:
Step-by-step explanation:
≈ 
First, factor out 5:
5 (x² -x -20)
We need two numbers that add to -1 and multiply to -20. -5 and 4 satisfy this.
5(x-5)(x+4)
Answer:
6.25 gm left
Step-by-step explanation:
Find the number of half lives in 26.3 years
26.3 / 5.26 = 5 half lives
(1/2) ^5 = 1/32 nd of the original will be left
1/32 * 200g = 6.25 gm left
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.