Answer:
1. We can see that salesperson's weekly income is the sum of her constant weekly salary ($760) and a commission which is variable and depends on her weekly sales.
So, if we say that y is her weekly income and x is her weekly sales, we can write this as:
y = 760 + 0.075x
Note that we had to change percentage to decimal number dividing it by 100.
2 Since for each value of x there is only one corresponding value of y, we can say that this is a function. For any value of x we input there is only one solution we get - that is the main feature of function and a way to tell if something is really a function.
Since this is a function, it can also be written as:
f(x) = 760 + 0.075x
3. Domain of a function is, basically, set of all values of x for which the function can work. That practically means that, since x is weekly sale, it can not be negative (one cannot make -$500 sale, for example). However, it is possible that she doesn't make a sale one week, making it possible for x to be 0. Also, the value of her sales doesn't have to be integer (it is quite possible that she makes $673.50 sale).
All this means that appropriate domain for this function are positive real numbers including 0.
Cone details:
Sphere details:
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From the endpoints (EO, UO) of the circle to the center of the circle (O), the radius is will be always the same.
<u>Using Pythagoras Theorem</u>
(a)
TO² + TU² = OU²
(h-10)² + r² = 10² [insert values]
r² = 10² - (h-10)² [change sides]
r² = 100 - (h² -20h + 100) [expand]
r² = 100 - h² + 20h -100 [simplify]
r² = 20h - h² [shown]
r = √20h - h² ["r" in terms of "h"]
(b)
volume of cone = 1/3 * π * r² * h
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To find maximum/minimum, we have to find first derivative.
(c)
<u>First derivative</u>

<u>apply chain rule</u>

<u>Equate the first derivative to zero, that is V'(x) = 0</u>




<u />
<u>maximum volume:</u> <u>when h = 40/3</u>


<u>minimum volume:</u> <u>when h = 0</u>

