Anyone good at math?

Question

I have been trying to figure it out all day and I just can't. I have emailed a math tutor, I'm still waiting on his response. My professor is going to be conducting an online chat tonight at 10:30 and I plan on being there for that, so don't tell me to do my own homework because I'm trying, I just don't get it! Here's the problem:
I am creating a chart to show a company's revenue. The formula is
Total Costs=Variable Costs + Fixed Costs
C(x)=mx+y
where x represents the number of items produced, m represents the cost to produce each item, and y represents the fixed costs.
These are the graphs I have to create:
Quadratic
Polynomial
Rational
Exponential and
Logarithm.
I could figure out the graphs using Excel but I need the equations. Please don't try to explain it to me using a bunch of math lingo and mumbo jumbo because I don't understand it at all. Just give me the equations.

Answer 1

Your total cost equation is linear (a line), it is also a polynomial.

Quadratic means polynomial of degree 2. You should see an x squared in your equation. You could use x*C(x). I do not know what the interpretation for that will be.

Rational means a quotient of polynomials. Say total cost per unit. Divide C(x) by x.

How can you have exponential and logarithmic in costs??
Change your C(x) to e^(mx) + y???
or ln(mx) + y??

d:

Answer 2

If the formula C(x) = mx + y remains unchanged and you are simply graphing it with different coordinate systems,
(changing C(x) = mx + y to C(x) = mx + b so I can use y for dependent variable)
Quadratic
y = √(mx + b)
Polynomial
y = (mx + b)^(1/n)
where n is the degree of the polynomial desired.
Rational
-- no clue --
Exponential
y = ln(mx + b)
and
Logarithmic
y = e^(mx + b)

If you are finding different equations,
Quadratic
C(x) = a + bx + cx^2
Polynomial
C(x) = a + bx + cx^2 + . . + mx^n
Rational
-- still no clue, unless it's
C(x) = a + b/x
Exponential
C(x) = a + be^cx
Logarithmic
C(x) = a + bln(x) or
C(x) = a + bln(x + c)

Answer 3

Still use Excel, Chart, Add trend line, select your curve, Options, check Display equation on chart.