The rectangle problem:
First, create some variables.
w = width
l = length
Then you know that the length is 3 times the width, so
l = 3w
The equation for perimeter is
P = 2(l+w)
Now you use substitution, substituting the 3w for l because you found that earlier.
P = 2((3w) + w)
And simplify.
P = 2(4w)
P = 8w
And you know P = 30 because they told you that.
30 = 8w
w = 15/4 inches, or 3.75 inches
Now substitute that value back into that first equation,
l = 3w
l = 3(15/4)
l = 45/4 inches, or 11.25 inches.
The dimensions are 11.25in for length and 3.75in for width.
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The volleyball problem:
100 minutes of stretching and scrimmaging combined, and you know 10 have to be stretching, so 90 is scrimmaging.
s = scrimmaging
T = total time
s = 2/3T (they gave you this)
90 = 2/3T
T = (90*3)/2
T = 270/2
T = 135 minutes, or 2 hours and 15 minutes.
Answer:
see below
Step-by-step explanation:
(a) the graph is symmetrical about the horizontal axis. It has a maximum value of r = 3 at θ = π.
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(b) The graph is symmetrical about both the horizontal and the vertical axis. It has a maximum value of r = 1 at θ = 0 and θ = π. (Note this curve has subtle differences from the inner loop of the above curve.)
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<em>About how</em>
As with any graphing problem, when doing it by hand, one chooses enough points to give the general shape of the curve. In some cases, quite a few points may be required. It is often helpful to use a spreadsheet for calculating the point values. Here, we've graphed the equations using "technology"--a graphing calculator.
Factor x^5 - x to get x(x^4 - 1) = x(x^2-1)(x^2+1) = x(x-1)(x+1)(x^2+1)
We see that x = 0, x = 1 and x = -1 are the real number roots or x intercepts. Ignore the complex or imaginary roots. Unfortunately, the graph shows the x intercepts as -2, 0 and 2 which don't match up.
So there's no way that the given graph matches with f(x) = x^5-x.
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As more proof, let's consider the end behavior.
As x gets really large toward positive infinity, x^5 will do the same and so will x^5-x. Overall, f(x) will head off to positive infinity. Visually, moving to the right will have the graph move upward forever. This is the complete opposite of what is shown on the graph.
Likewise, the left endpoint should be aimed down instead of up. This is because x^5-x will approach negative infinity as x heads to the left.
In short, the graph shows a "rises to the left, falls to the right" end behavior. It should show a "falls to the left, rises to the right" pattern if we wanted to have a chance at matching it with x^5-x. Keep in mind that matching end behavior isn't enough to get a 100% match; however, having this contradictory end behavior is proof we can rule out a match.
I recommend using Desmos, GeoGebra, or whatever graphing program you prefer to plot out y = x^5-x. You'll get a bettter idea of what's happening.
