Post 12

so,
This week I stressed out over Calculus a little too much because of the test (thus causing me to forget to do my blog/comments…I’m still kicking myself for that one). But maybe it actually paid off because I did rather well on my test…I think. So for things I understand like 100 percent:

Limits: if you can’t just plug in the number it approaches (which is when you get a zero on the bottom), you have to manipulate algebra and cancel out anything that can be and then plug in the number. If that doesn’t work, you then can try to use your table function. Then if That doesn’t work, it is DNE.

Optimization: Identify primary and secondary. Solve secondary for 1 variable (if applicable) and plug into primary. Take derivative of primary to solve for other variable and plug into the secondary equation to find the other variable. (Confusing I know…but it’s not that difficult…patience)

Example:
The sum of two numbers is 120. The product of the two is 7200. Find the minimum values

Set up equations: x + y = 240
xy = 7200

Solve the secondary for, let’s pick, y. So, y = 240-x.

Plug into primary

x(240 – x) = 7200

Take Derivative

1(240 – x) + (-1)(x) = 0

Solve for x.

x=120

Plug into when we solved y.

y=120

Simple enough right? So apply that same principle to other problems like when finding dimensions and area.

Related Rates: Everything is in reference to time. You have to be able to identify your formulas and everything that’s given out of words. Get what I’m saying? And remember that speed can’t be negative (made that mistake a few times). Also, don’t forget your units!!!!
And, thanks to Milky, I now know how to do the derivative graphs…I think, once again. Like if they give you the derivative graph, all of the zeroes are your maxima and minima. You determine which is which by looking at where it’s below or above the axis.

So, in short, I think I’m pretty much ready to move on and get done with Calculus…for the time being. However, one thing I have a little trouble with is percent error. If someone could, by any means, explain how exactly those work, it would be greatly appreciated.

Hope some of my stupid explanations helped someone, but don’t blame me if they confuse you even more (some things sound really good in my head….they just don’t come out too well…). So, yyyyyyyyyyeeeeeeeeeeeaaaaaaaaaaaaaaaa…………………




BYE!