×

# Impossible Integral

Is it possible to find $$\int\sin(\sin\theta)\mbox{ d}\theta$$?

Note by Kenny Lau
2 years, 3 months ago

Sort by:

I think ... the question is ill posed. Indefinite integrals don't have a "value". Sometimes you can't have a closed formula for some functions, yet for specific limit values you cand find out the exact integral value · 2 years, 3 months ago

Thanks for your reminder. I've updated the question. · 2 years, 3 months ago

Assume \sin\theta =t We have \cos\theta dø = dt,by difrentiat it \cos\theta =\sqrt{t^{2}-1} So new function is \frac{ \sin\theta }{\sqrt{t^{2}-1} Solve this function by part ,may be we a solution · 2 years, 3 months ago

$t=\sin\theta$ $\frac{\mbox{d}t}{\mbox{d}\theta}=\cos\theta$ $\mbox{d}\theta=\frac{\mbox{d}t}{\sqrt{1-t^2}}$ $\begin{array}{rcl} I&=&\int\sin(\sin\theta)\mbox{ d}\theta\\ &=&\int\frac{\sin t\mbox{ d}t}{\sqrt{1-t^2}} \end{array}$ · 2 years, 3 months ago