Part A. You have the correct first and second derivative.
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Part B. You'll need to be more specific. What I would do is show how the quantity (-2x+1)^4 is always nonnegative. This is because x^4 = (x^2)^2 is always nonnegative. So (-2x+1)^4 >= 0. The coefficient -10a is either positive or negative depending on the value of 'a'. If a > 0, then -10a is negative. Making h ' (x) negative. So in this case, h(x) is monotonically decreasing always. On the flip side, if a < 0, then h ' (x) is monotonically increasing as h ' (x) is positive.
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Part C. What this is saying is basically "if we change 'a' and/or 'b', then the extrema will NOT change". So is that the case? Let's find out
To find the relative extrema, aka local extrema, we plug in h ' (x) = 0
h ' (x) = -10a(-2x+1)^4
0 = -10a(-2x+1)^4
so either
-10a = 0 or (-2x+1)^4 = 0
The first part is all we care about. Solving for 'a' gets us a = 0.
But there's a problem. It's clearly stated that 'a' is nonzero. So in any other case, the value of 'a' doesn't lead to altering the path in terms of finding the extrema. We'll focus on solving (-2x+1)^4 = 0 for x. Also, the parameter b is nowhere to be found in h ' (x) so that's out as well.
So,
We know that we cannot add or subtract quantities of the same kind.
-18xy can only be added/subtracted to 4yx, which is the same as 4xy. The result would be -14xy, or -14yx.
The correct option is B.
The volume of the prism is calculated by multiplying the length, L, width,W, and depth or height, H.
V = L x W x H
Fish tank:
V = 50 cm x 25 cm x 25 cm
= 31250 cm³
Depth of the water in tank (with castle - without castle)
d = 57.5 cm - 48 cm = 9.5 cm
Volume of the caste:
V = 9.5 cm x 50 cm x 25 cm = 11875 cm³
