I'm in a tight call now. Been trying to understand my maths for the upcoming exam from now monday, but can't figure out how to do the exercises. Been asking around for help, sent my bro with some examples to ask his math teacher, but no help from anywhere, yet monday's creeping closer and closer, so I'll ask here. Anybody here that can explain me how to solve these types of questions? Some examples... (if some words seem odd, that'd be due to bad translation then)
(a) Prove that the function f : x -> x^5 - x - 1 has exactly one zeropoint in the interval [0,2].
(b) Near this zeropoint with the bisection-method with an error that's smaller than 10^-1.
(c) How many steps are needed to calculate the zeropoint with an error that's smaller than 10^-12?
Be D the area
D = {(x,y) e R^2 | x > 0, y > 0, x + y < 2, x^2 + y^2 > 2}.
(a) Make a sketch from D.
(b) Calculate the integral ?D? 1/(x^2 + y^2)^2 dx dy.
Math problems
Re:Math problems
The integral changes direction (up/down) exactly once. Not sure if that's of any help...Kon-Tiki wrote: (a) Prove that the function f : x -> x^5 - x - 1 has exactly one zeropoint in the interval [0,2].
Thought:
x^5 = x+1
Not nice to call it R^2, call it RxR.Be D the area
D = {(x,y) e R^2 | x > 0, y > 0, x + y < 2, x^2 + y^2 > 2}.
(a) Make a sketch from D.
(b) Calculate the integral ?D? 1/(x^2 + y^2)^2 dx dy.
See this as a plain graph with X and Y, where you draw an area of all combinations of X and Y, where X > 0 (draw a line there), Y > 0 (line there), x+y<2 (line there) and x^2+y^2 > 2 (line there). Three straight lines, one angled parabole. The first two delimit you to the upper right hand quarter. The other two define an area (between the lines). That's D.
The point of integrating a set (or an area) is completely beyond me.
[edit] no hyperbole [/edit]
Re:Math problems
Why I'd need to know these's beyond me. Seems like making a quick program to draw it for me's easier... even in QBasic. Anyways, thanks for the quick reply Still will be hard as hell to solve similar questions, but then again, I've never been a math wizz.
Re:Math problems
w00t! Friend of mine gave me this link. Can continue my studying again
Re:Math problems
And you would draw... which interval? From -100 to +100? Are you sure that would cover any zeropoints?Kon-Tiki wrote: Why I'd need to know these's beyond me. Seems like making a quick program to draw it for me's easier...
The idea is that you should be able to write a program that finds the zeropoints without drawing the graph and parsing it again...
(I don't say I'd be able to do it myself. The last five years I've worked in the software industry with blissfully few "encounters" with math...)
Every good solution is obvious once you've found it.
Re:Math problems
Fifth exercise, in the solution, how'd they get -6? I'd say that, logically, the outcome'd be non-existing, due to division by 0...
Edit: Nevermind. Got it
Edit: Nevermind. Got it