@satellite73 @solomonzelman
@SolomonZelman @jim_thompson5910
\(\color{#000000}{ \displaystyle \int \frac{1+\cos x}{\sin x} dx }\) \(\color{#000000}{ \displaystyle \int \frac{1}{\sin x} dx +\int \frac{\cos x}{\sin x} dx }\) or do you want an easier approach?
you don't get a notification unless you post...which you just did lol @chosenmatt
Whatever works is fine.
Yeah, the integral for csc(x), and for tan(x)....
oh, duh
cos/sin = cot, not tan
yes, thanks jim. What the hack am I saying? :)
wait, I don't know the integral for csc and cot...?
My book only has for csc^2
We can proof the formulas for them, or you can just use the formula for them/
it is just the matter of willingness.
since I have to get my homework done soon, I'm gonna go with formula. Then, after, you can show proof
if it was me, i would look in the back of the book almost all of calc 2 is right there on two pages
If it was me, I would just use mathematica))
lol or wolframalpha (in the browser already)
the book says the integral of cot is ln|sin x| + C
I checked the back
that one is a simple u - sub
oh, right
it is \[\int \csc(x)dx\] you need to look up
ok
-ln|csc x - cot x| + C
Is that right?
\(\color{#000000}{ \displaystyle \int \frac{1+\cos x}{\sin x} dx }\) \(\color{#000000}{ \displaystyle \int \frac{2+e^{ix}+e^{-ix}}{e^{ix}-e^{-ix}} dx }\) yeah, either way you end up with the same thing, although in a bit different form:)
You are right about the ln
got my book right here, let me check
You can get that by multiplying the numberator and denominator by csc+cotx and negating the top to get integral of -1/u form
Integral of cot(x)dx is simplier.
my book does not have the minus sign
weird? mine does...?
\[\ln(\csc(x)-\cot(x))\]
maybe it doesn't matter...?
possible we can check by differentiation
Idk why I even have to use that formula when I haven't even learned it yet
It does and there should be a minus
that is the point of a formula you don't have to learn it, just look it up
-ln abs(cotx+cscx)
maybe my Stewart has a typo i think he just passed away
Why it's important to recognize the steps needed for that result
\[\log(\csc(x)-\cot(x))\] is definitely right just check it
??
multiply cscxdx by cotxcscx / cotxcscx you get csc^2+cotxcscx / cotx+cscx yeah?
right?
The first time I integrated \(\csc x\) in my life, I remember, I ended up with. \(\color{#000000}{ \displaystyle \int\frac{1}{\sin x}dx =\int\frac{\sin x}{1-\cos^2x}dx }\) Sub, \(u=\cos x\) \(du=-\sin x dx\) \(\color{#000000}{ \displaystyle -\int\frac{1}{1-u^2}du=\int\frac{1}{u^2-1}du }\) Partial Fractions, \(\displaystyle \frac{1}{u^2-1}=\frac{A}{u+1}-\frac{B}{u-1}\) \(\displaystyle 1=A(u-1)-B(u+1)\) \(\displaystyle B=-1/2\) \(\displaystyle A=1/2\) \(\color{#000000}{ \displaystyle \int\frac{1}{u^2-1}du=\int\frac{1/2}{u+1}du-\int\frac{1/2}{u-1}du = }\) \(\color{#000000}{ \displaystyle \frac{1}{2}\ln(\sin x+1)-\frac{1}{2}\ln(\sin x-1) = }\) \(\color{#000000}{ \displaystyle \frac{1}{2}\ln\left(\frac{\sin x+1}{\sin x-1}\right)+C }\)
it is not very hard to proof these, just using u-substitution and an algebraic technique of partial fractions.
Oh, I left of absolute value. Sorry.
Good luck with integration:)
And it u=cosx so your answer should involve cosine
Is the answer ln|1-cos x| + c?
Yes, cosine instead of sine....
I overworked myself. gtg
lol, thanks
\[\int\limits cscx dx = \int\limits - (-\csc^2(x)-\cot(x)\csc(x))/\cot(x)+\csc(x) = \int\limits \frac{- 1 }{ u}du= -\ln \left| \cot(x) +\csc(x) \right| +C\]
u= cot(x) + csc(x) du= -csc^2(x) - csc(x)cot(x)
So hopefully this convinces you that -ln... is the solution
Join our real-time social learning platform and learn together with your friends!