Ask your own question, for FREE!
Mathematics 6 Online
OpenStudy (math2400):

antiderivative problem

OpenStudy (math2400):

OpenStudy (adi3):

does F'(0) means that f wont be included in the sum

OpenStudy (math2400):

i'm not sure....

OpenStudy (adi3):

@butterflydreamer

OpenStudy (xapproachesinfinity):

well first find f' from f''

OpenStudy (math2400):

can u show me how?

OpenStudy (math2400):

please :)

OpenStudy (xapproachesinfinity):

\[f''(x)=6x+6\sin x \Longrightarrow \int 6x+6\sin x dx=f'(x) \\ 3x^2-6\cos x+c=f'(x) \]

OpenStudy (math2400):

so i do the anti derive. again?

OpenStudy (xapproachesinfinity):

through the givens we can find c f'(0)=3(0)-6cos0+c=3 -6+c=3 c=9 so \[f'(x)=3x^2-6\cos x+9\]

OpenStudy (math2400):

ok

OpenStudy (xapproachesinfinity):

yes you have to apply the anti derive one more time to get to f

OpenStudy (math2400):

so i got x^3 - 6sinx

OpenStudy (math2400):

then i'd need the c I'm guessing?

OpenStudy (xapproachesinfinity):

x^3-6sinx +c then find the c again

OpenStudy (xapproachesinfinity):

yah you are given that f(0)=3

OpenStudy (math2400):

it it 9 then?

OpenStudy (math2400):

wait no

OpenStudy (xapproachesinfinity):

no solve don't just guess!

OpenStudy (math2400):

3

OpenStudy (math2400):

cuz u plug in zero into the equation and then set it equal to 3?

OpenStudy (xapproachesinfinity):

yes

OpenStudy (xapproachesinfinity):

exactly!

OpenStudy (freckles):

well ...

OpenStudy (freckles):

I think someone forgot to integrate 9 earlier

OpenStudy (freckles):

what did you get for f(x) given \[f'(x)=3x^2-6\cos x+9\]

OpenStudy (math2400):

i got x^3 - 6sinx

OpenStudy (freckles):

why ignore the 9?

OpenStudy (math2400):

oppss

OpenStudy (math2400):

got it thanks!!

OpenStudy (freckles):

recall (9x+d)'=(9x)'+(d)'=9+0=9 so you get f(x)= x^3-6sin(x)+9x+d then you find the constant d using f(0)=3

OpenStudy (xapproachesinfinity):

eh i forgot the constant 9 too :) got catch @freckles

OpenStudy (freckles):

My kitty told me about it.

OpenStudy (xapproachesinfinity):

good catch i mean :) kitty haha

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!