Let X be a normal random variable with mean 40 and standard deviation 2. Find P(X < 28).
1 answer:
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Answer:
2) 162°, 72°, 108°
3) 144°, 54°, 126°
Step-by-step explanation:
1) Multiply the equation by 2sin(θ) to get an equation that looks like ...
sin(θ) = <some numerical expression>
Use your knowledge of the sines of special angles to find two angles that have this sine value. (The attached table along with the relations discussed below will get you there.)
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2, 3) You need to review the meaning of "supplement".
It is true that ...
sin(θ) = sin(θ+360°),
but it is also true that ...
sin(θ) = sin(180°-θ) . . . . the supplement of the angle
This latter relation is the one applicable to this question.
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Similarly, it is true that ...
cos(θ) = -cos(θ+180°),
but it is also true that ...
cos(θ) = -cos(180°-θ) . . . . the supplement of the angle
As above, it is this latter relation that applies to problems 2 and 3.
The given three numbers are 5,8,24.
We have to use four operations (Adding, Subtracting,multiplication, division, square, square root, cube, cube root) out of these operation to make the result an irrational number.
There are many more examples that you can write.
Keep in mind
1. Sum of Rational and irrational is always irrational.
2. Difference of rational and irrational is always irrational.
As none of the 5,8,24 is a perfect square , nor addition of any two results in a perfect square, so square root of their addition or subtraction or multiplication results in an irrational number.
Similarly ,apart from 8, none of 5,24 is a perfect cube.So if you add or subtract any number from 8 and take their cube root or square root ,results in an irrational number.