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marleca

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I have an idea on what I am supposed to do but, I need some reassurance to know if I am doing this correctly. The question reads: you own a silk screening business that prints designs on t-shirts. The model for the average cost per shirt is:

a= 2.75x + 150/ x

where x is the number of shirts in the production run, $ 150 is the one time charge fir creating the design and supplies, and 2.75 is the cost of the plain shirt. sketch a graph of the equation.

In order to get the equation will i put it in y=mx+b form? I am not not exactly sure hoW i will do this inorder to sketch a graph. help.
 
marleca said:
I have an idea on what I am supposed to do but, I need some reassurance to know if I am doing this correctly. The question reads: you own a silk screening business that prints designs on t-shirts. The model for the average cost per shirt is:

a= 2.75x + 150/ x

where x is the number of shirts in the production run, $ 150 is the one time charge fir creating the design and supplies, and 2.75 is the cost of the plain shirt. sketch a graph of the equation.

In order to get the equation will i put it in y=mx+b form? I am not not exactly sure hoW i will do this inorder to sketch a graph. help.
Click to expand...

You did not complete your question - what were you asked to do?
 
For sketching the graph - assume different values of 'x' and calculate 'a'.

Make a table - and plot the value of 'a' along y-axis for each 'x'.

The curve will not be a straight line - so you cannot transform the equation into y = mx + b form.

[edited the line out because the original equation was mis-understood]

So I would plot the curve by choosing x = 5, 10, 15 ....50, 55, 60, 65, 70

Then calculate 'a' for x = 350
 
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Okay, i think i understand. Are you saying to choose random numbers for x, and plug it in to the equation given. once i do that and get an answer, that will be the coordinates I will use to plot on graph?
 
Yes, that is correct, as long as your random numbers for x are positive numbers.

When you find values of a, by substituting positive numbers for x, you'll have coordinates of points in the form (x ,a).

In this exercise, they have changed the name of the y-axis; they are calling it the a-axis.

In other words, symbol a is just another name for y, in this exercise, so you can think of the given equation like this:

y = (2.75x + 150)/x​


When you label the axes on your graph, just make sure that you label the vertical axis "a" instead of "y".




Also, will you please note the grouping symbols (in red) that I inserted above?

These are very important, to show that the expression (2.75x + 150) is the numerator of this rational function.

You left off the grouping symbols, in your post.

Because of the Order of Operations, typing 2.75x + 150/ x means \(\displaystyle 2.75x + \frac{150}{x}\).

Typing (2.75x + 150)/x instead means \(\displaystyle \frac{2.75x + 150}{x}\).


Cheers ~ Mark :cool:
 
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Oh, I just discovered that this thread is a duplicate discussion.

The other discussion that you started on this same exercise is HERE.

Please do not post the same exercise more than once, on the boards. It's too confusing for everybody to jump back and forth between two different threads on the same topic.

If you want to say something additional about your exercise, just add a new post to the original thread; do not start a second thread.

Thank you.
 
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