Currently studying for my Calculus exam on Monday but am stuck on some particular problem.
I took the first derivative and got:
12x^2 + 30x + 18
Then I factored it:
6(2x^2 + 5x + 3)
Used the quadratic formula and got x=1 and x=1.5
My question is... what do I do after that? srs
Thanks in advance.
(I know there's an official math thread but I would literally have to wait a few days before getting an answer)


05032012, 11:53 PM #1
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set the derivative equal to 0. solve for x. plug x back into original equation.
edit: your derivative is completely wrong. da fug mayne.
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05042012, 12:37 AM #23
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Alright, here we go.
This is from the '11 test.
f'(x)= 6x^2  18x  24
6(x^2  3x  4)
Quadratic formula
x=4;x=1
x=4
x=1
x=2
x=7
Plug all of these numbers into the original equation and I get
x@2= 11
x@1= 28
x@4= 97
x@7= 92
Abs max = f(7)
Abs min = f(4)
Does that look correct?War is Peace; Freedom is Slavery; Ignorance is Strength.

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f'(x) = 6x^2  18x  24
6(x^2 3x 4)
6(x4)(x+1)
x=4
x=1
f(4)
f(1)
f(0)
f(2)
f(7)
I didn't plug them in but I think you're good to go OP. Good job.
Just a something to remember for the exam, incase your professor tries to phuck with you:
If any of your roots are not in the intervals given, then you don't have to plug them in.
So if you had an x = 8 in this case, you would just ignore it.◄ Stim Dick Mafia ►
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