Answer: sqrt(2)/2 which is choice D
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Explanation
(3pi/4) radians converts to 135 degrees after multiplying by the conversion factor (180/pi).
The angle 135 degrees is in quadrant 2. We subtract the angle 135 from 180 to find the reference angle
180-135 = 45
Then you can use a 45-45-90 triangle to determine that the ratio of opposite over hypotenuse is sqrt(2)/2
sine is positive in quadrant 2
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Alternatively, you can use a unit circle. Refer to the diagram below. In red, I've circled the angle 3pi/4 radians. The terminal point for this angle has a y coordinate of sqrt(2)/2
Recall that y = sin(theta).
Answer:
(a) 0.4
(b) a = 3
Step-by-step explanation:
(a) The area under the curve from x=4 to x=6 is 0.2 units high and 2 units wide, so is 0.2·2 = 0.4. (The area of a rectangle is the product of length and width.)
(b) The area is 0.2 and the height of the curve is 0.2, so the width of the region of concern is 0.2/0.2 = 1. (Again, area = height·width, or width = area/height.) 1 unit from the left end is found at X=3, so a = 3.