Answer:
The angle of DC is 130°.
Step-by-step explanation:
Given tha total angle in a centre(O) of circle, is 360. So in order to find ∠DOC, you have to subtract 85° and 145° from 360° :
∠COD = 360° - ∠COE - ∠DOE
= 360° - 85° - 145°
= 130°
Problem 1
With limits, you are looking to see what happens when x gets closer to some value. For example, as x gets closer to x = 2 (from the left and right side), then y is getting closer and closer to y = 1/2. Therefore the limiting value is 1/2
Another example: as x gets closer to x = 4 from the right hand side, the y value gets closer to y = 4. This y value is different if you approach x = 0 from the left side (y would approach y = 1/2)
Use examples like this and you'll get the results you see in "figure 1"
For any function values, you'll look for actual points on the graph. A point does not exist if there is an open circle. There is an open circle at x = 2 for instance, so that's why f(2) = UND. On the other hand, f(0) is defined and it is equal to 4 as the point (0,4) is on the function curve.
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Problem 2
This is basically an extension of problem 1. The same idea applies. See "figure 2" (in the attached images) for the answers.
It is not correct.
The student found the volume by multiplying the base area with the height. He forgot to divide it by 3.
Formula to find the volume of the pyramid = 1/3 base area x height
volume = 1/3 x 92 x 54 = 1656 square meters