Ask your own question, for FREE!
Mathematics 7 Online
OpenStudy (anonymous):

Integral Question

OpenStudy (anonymous):

f(x)=\int_1^{3x^5} \ln(t^2+1) \, dt

OpenStudy (anonymous):

\[f(x)=\int_1^{3x^5} \ln(t^2+1) \, dt\]like that?

OpenStudy (anonymous):

is the question find the derivative?

OpenStudy (anonymous):

yes it is,

OpenStudy (anonymous):

how'd i guess?

OpenStudy (anonymous):

too hard to integrate

OpenStudy (anonymous):

use the chain rule. the derivative of the integral is the integrand, so replace t by \[3x^5\] and then multiply the answer by \[15x^4\]

OpenStudy (anonymous):

yeah im having trouble with these. Ill try it sat!

OpenStudy (anonymous):

\[f'(x)=\ln((3x^5)^2+1)\times 15x^4\]

OpenStudy (anonymous):

i should have let you do it on your own, but once you see it you should realize how easy it is. it is clear what i did yes?

OpenStudy (anonymous):

if you need a word of explanation let me know

OpenStudy (anonymous):

i understand chain rule for ln (function within function). where did the 15x4 come from?

OpenStudy (anonymous):

nvm 3x^5 derivative

OpenStudy (anonymous):

15x^4 \ln(9x^{10}+1) ?

OpenStudy (anonymous):

yes

OpenStudy (anonymous):

it is the chain rule and you have a composite function. don't forget that \[F(x)=\int_a^x f(t)dt\] is a function of "x" so if you do not have an x in the upper limit, but rather something else, you have a composition like \[F(g(x))=\int_a^{g(x)}f(t)dt\] and so you need the chain rule

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!