Answer:
A)
Step-by-step explanation:
An equation is a function of when
is the independent variable, that is:
(1)
Where is the dependent variable.
According to this, does not represent a function of
, since the independent variable is a function of
, that is,
. Therefore, the correct answer is A.
f(x) = 5(1.25)x + 4
<h2>Explanation</h2>To solve this, we are going to use the standard exponential equation:
where
is the initial amount
is the growth rate in decimal form
is the time (in months for our case)
Since the hours of classic music remain constant, we just need to add them at the end. We know form our problem that Sue initially has 5 hours of pop, so ; we also know that every month onward, the hours of pop music in her collection is 25% more than what she had the previous month, so
. Now let's replace the values in our function:
Now we can add the hours of classical music to complete our function:
I find it convenient to look at the differences and the rate at which those differences are made up.
8. Jim is closing the $150 gap at the rate of $7.50 per week. He will catch up in
... 150/(7.5/week) = 20 weeks
9. At noon, the price of Stock A has increased by 0.05×3 = 0.15, so is now $15.90, which is $0.63 more than Stock B at that time. The prices are closing the gap at the rate of $0.05 +0.13 = $0.18 per hour, so will be the same after
... $0.63/($0.18/hour) = 3.5 hours . . . . after noon, at 3:30 pm
_____
You can also write and solve equations for the prices of the stocks. Or you can use a graphing calculator to tell you the solution. When equations are involved, I like to solve them the simplest possible way: let technology do it.
You are given the value at a time, and the rate of change of that value, so the equations are easily written in point-slope form. You will note that the common price at 3:30 pm (15.5 hours after midnight) is one that is not a whole number of cents. (That's usually OK for when trading stocks.)
