Saturday, September 18, 2010

H2 #1 b

I got stranded on this problem last week and I still can't figure it out:

I understand how to use the bisection method to find a root, we know we are looking for where y=0, but how do we do this for an unknown value? I understand that I am going to have to eventually subtract the f(eq1) from f(eq2) but unless I know how they both work, I don't know how to move the midpoint... if that even makes sense

OKAY, NEVER MIND, GOT IT

I know the problem was already due, but it stumped the crap out of me and I know some other people had trouble as well so hopefully this can help them:


1b. Determine the intersection of the equations x^3-2x+1 and y=x^2 correct to 6 decimal places.


Step 1: populate the list with a0, bo, c0, f1(a0), f1(b0), f1(c0), f2(a0, f2(b0), f2(c0)

Step 2: What you need to do here is compare the signs again: the difference here between #1 is that you are comparing the sign of 'the distance of the 2 functions of c' to 'the distance of the 2 functions of a and b'. Beyond that it is the same process.

3 comments:

  1. i'm not clear on what you mean for step 2. when you say distance of the 2 functions you mean f1(a)-f2(a) not the abs(f1(a)-f2(a)) correct?

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  2. any way you can disable the word verification when i post a comment?

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  3. yeah, I should have been more clear

    instead of checking "sign(a0)" against "sign(c0)" or whatever we did in the first problem you have to check distance.

    specifically:
    -if(SIGN(f2(a0)-(f1(a0)) = SIGN(f2(c0) - f1(c0); change the value to c0; otherwise keep it the same.

    I'll see about disabling the CAPTCHA

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