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GalinKa [24]
2 years ago
8

The exact value of cos 17pi/8 is . . a) square root of 2+the square root of 2/4 . b.) 0.38. c.) 0.99. d.)square root of 2-the sq

aure root of 2/4
Mathematics
1 answer:
alexgriva [62]2 years ago
7 0
Cos(17pi/8)

cos(17π/8)

But π radians = 180°

17π/8 radians = (17/8) * 180 = 382.5

But this is more than 360°,  so we have the basic angle by subtracting 360°

382.5 - 360 = 22.5

cos(17π/8) = Cos22.5

Recall double angle formula for cos.

cos2θ = 2cos²θ - 1

Therefore

cos(2*22.5) = 2cos²(22.5) - 1

cos45 = 2cos²(22.5) - 1

(√2)/2  =  2cos²(22.5) - 1

2cos²(22.5) - 1 =  (√2)/2


2cos²(22.5)  = (√2)/2 + 1

 2cos²(22.5)  = (2 + √2) / 2

cos²(22.5) = (2 + √2) / 4

cos22.5  =   √( (2 + √2)/4) ................(note)

cos22.5 = √(2 + √2) / 2

Option (a) seems like the closest, comparing to (note) above.
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Let sugar be the explanatory variable and calories be the response variable; which scenario best describes ŷ = 57 + 2.5x?
algol13

Answer: Choice E)

The amount of calories in fruit juice increases by 2.5 for every one gram of sugar. The calorie amount estimated by this model is 57 if there are zero grams of sugar.

=============================================================

Explanation:

x = amount of sugar (in grams)

y = number of calories in the juice

ŷ = estimate of y, so its the estimate of calories in the juice

The regression equation rearranges to ŷ = 2.5x + 57

This is in the form y = mx+b where m = 2.5 is the slope and b = 57 is the y intercept.

The slope tells us what the rate of change is. Specifically, it tells us how much the amount of calories (y) is going up each time the amount of sugar (x) goes up. Each time x goes up by 1, y goes up by 2.5

The y intercept 57 is the starting or initial amount of calories. If you have 0 grams of sugar, the lowest amount of sugar possible, then you start off with 57 calories. We can see this by plugging x = 0 into ŷ = 2.5x + 57 (you should get ŷ = 57). Visually, the y intercept is where the line crosses the y axis.

All of these facts point to choice E as the final answer.

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If it snows tomorrow the probability is 0.8 that John will practice his trombone if it does not snow tomorrow there is only a 0.
Bas_tet [7]

Answer:

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Step-by-step explanation:

Given that :

P(trombone | snow) = 0.8 ;

P(trombone | no snow) = 0.5

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3 years ago
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Answer:

Total length of running track is 371.24 m .

Step-by-step explanation:

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