post 14 & 15

first off, i'd like to say HAPPY BIRTHDAY TO ME & MAMIE! :) :) :)

secondly, sorry i forgot about my blog last weekend, so i'm gonna do just like steph and do two in one.

POST #14

so basically this past week we've just been reviewing integration. with definite and indefinite integrals, how to not use product and quotient rule, how to integrate something with a trig function, and all that good stuff. we also learned substitution. this is when you set something in the problem equal to u and something else in the problem equal to du. typically the part of the problem that looks like the derivative of the other half is du.

i was getting really good at substitution right before the holidays, but lucky me, i left my binder at school over thanksgiving break, and now it's almost completely left my mind. i'll try and explain it the best i can though.

after fiding u and du, you then plug in u and du back in. let's say you had f(x) = (cos^2(X))(-sin(x)) dx

u = cos(x) du=-sin(x)
f(x) = u^2 du dx

then you would plug cos(x) back into u, and du dx cancels out
f(x)=c0s^2(x)

and i'm pretty sure that's how you do it.. if i'm wrong please correct me! that will be what i need help with for this blog

POST # 15

OK, so it's the last day of our holiday's and my birthday :) so obviously since we weren't at school we didn't learn anything new this week.

i'm gonna review limit rules, since we still have problems with limits sometimes.

if a limit is approaching any number, plug that number into the equation at x. solve for x, and that is your answer. if you can cancel out things in the equation, do that before you plug in for x and start solving. also, if the bottom is equal to 0, your answer is undefined. sometimes, when you can't plug in for x, you have to plug the entire equation into your calculator and go to the table function and see what number is approaching your limit. if you are given a limit approaching infinity, you have three basic rules:
1. if top degree is larger than bottom degree, it is equal to +/- infinity.*****
2. if top degree is smaller than bottom degree, it is equal to 0.
3. if top degree is euqal to bottom degree, then divide the leading coefficients.

*****to find out whether it is positive or negative infinity, you plug it into the graph on your calculator.

as easy as limits seem, they are still hard. especially whenever you have to use your table function in the calculator. also if do use your table function and the limit is approaching something with E in it, the answer is undefined. you can always use your table function to double check yourself but you don't have to.

the thing i still don't understand is LRAM, MRAM, RRAM. i guess i never really grasped it in the first place to ever understand it. we kinda learned it fast, and never really dealt with it after that. i'm just nervous because it's gonna be on the exam! i don't understand any of it, so if you do please give me a brief explanation, thanks! :)