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Explanation:
The full circle has a circumference of
C = 2*pi*r
C = 2*3.14*4
C = 25.12
Divide this by four because we only want a quarter circle (and not the whole thing). Imagine cutting a pizza into four equal slices, and we only focus on one slice.
The curved portion of the slice is roughly 25.12/4 = 6.28 units long.
Add on the two straight line portions of the quarter circle to get 6.28+4+4 = 14.28
The straight line portions are the radius.
The answer of 14.28 is approximate because pi = 3.14 is approximate.
47 -14i
You can work this out in the straight-forward way, or you can recognize that (6-i) is a common factor. In the latter case, you have ...
... = (6-i)(5 + 3-i)
... = (6 -i)(8 -i)
This product of binomials is found in the usual way. Each term of one factor is multiplied by each term of the other factor and the results summed. Of course, i = √-1, so i² = -1.
... = 6·8 -6i -8i +i²
... = 48 -14i -1
... =
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A suitable graphing calculator will work these complex number problems easily.
