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Re: A92: a92-a lot of questions




{{What answer does your calc give?}}

not the correct one..i've already found the answer to the integral part 
of the equation (in true calculus ways and my methods combined) and 
found that the answer the calc gives isn't the same.  i even assigned 
both of them equal to each other and solved, both of them came out 
unequal.

here:

integral(x^2*(x+1)^(1/2),x) is suppose to give:

2x^2*(x+1)^(3/2)/3-8x*(x+1)^(5/2)/15+16*(x+1)^7/2)/105

you can check that by taking the derivative and getting the above, but 
the calculator gives this answer:

2x^2*(x+1)^(3/2)/7-8x*(x+1)^(3/2)/35+16*(x+1)^(3/2)/105

if you think that the above two equations are the same then take the 
derivative of this one and see for yourself, you'll notice that it 
doesn't come out equal (if the calculators are the same as mine).

i'm calling this error RCD error (my name Rob Caldwell and D=derivative) 
just for naming purposes (since everybody likes to name everything they 
find).  until someone proves me wrong (you'll have to convince me by 
coming to my house and showing me on MY calculator) then i'll say that i 
was BSing the whole thing (but i'm not).

if anyone else has the RCD error post about having it.

-Rob
president
RCWare
Scratch Designs


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