Ask your own question, for FREE!
Mathematics 14 Online
OpenStudy (anonymous):

Help me solve this please!!!! f (e^-2x)sinxdx f (cos(ax))/(rad(9+sinax)) dx

OpenStudy (anonymous):

OpenStudy (jhannybean):

u substitution?

OpenStudy (anonymous):

can you show me step by step ?

OpenStudy (jhannybean):

\[u = 9+\sin(ax)~,~ du = a\cos(ax)dx\]

OpenStudy (jhannybean):

Oh there are 2 problems here.

OpenStudy (anonymous):

yeah i'm having trouble with them i haven't taken calc 1 in like a year so i'm trying to refresh my memory

OpenStudy (jhannybean):

\[\int e^{-2x}\sin(x)dx\]Use LIATE for determining the u substitution: 1. Log 2. Inverse 3. Algebraic (polynomials) 4. Trig 5. exponentials\[u=\sin(x)~,~ du = \cos(x)dx~,~ dv = e^{-2x}dx~,~v = \int e^{-2x}dx = -\frac{1}{2}e^{-2x}dx \]

OpenStudy (anonymous):

how do i solve the second one?

OpenStudy (jhannybean):

Integration by parts: \[\int udv = uv - \int vdu\]

OpenStudy (jhannybean):

For the second one.. look at my first post. \(\color{blue}{\text{Originally Posted by}}\) @Jhannybean \[u = 9+\sin(ax)~,~ du = a\cos(ax)dx\] \(\color{blue}{\text{End of Quote}}\)

OpenStudy (anonymous):

is -1/2e^-2xdx the final form?

OpenStudy (jhannybean):

No, you have to plug it into the format for integration by parts. \(\color{blue}{\text{Originally Posted by}}\) @Jhannybean Integration by parts: \[\int udv = uv - \int vdu\] \(\color{blue}{\text{End of Quote}}\)

OpenStudy (anonymous):

@Jhannybean can you show it to me plugged in?

OpenStudy (jhannybean):

I've already identified what your u, v , du, and dv are, all you have to do is plug them into the formula and solve

OpenStudy (jhannybean):

Simplify it*

OpenStudy (anonymous):

@Jhannybean how did you get the u, v, du, and dv

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!