Mathematics
7 Online
OpenStudy (anonymous):
find the integral of :
cosx/1-cos^2 dx
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OpenStudy (anonymous):
$$\int \frac {\cos x} {1 - \cos^2 x} \, \mathrm{d}x$$
From the normalization identity, we know that \(\sin^2 x = 1 - \cos^2 x\).
OpenStudy (anonymous):
Thus:
$$\int \frac{\cos x}{\sin^2 x} \, \mathrm{d}x$$
OpenStudy (anonymous):
Let us substitute \(u = \sin x\). Thus, \(\mathrm{d}u = \cos x \, \mathrm{d}x\).
OpenStudy (anonymous):
Sorry about previous answers, I meant:
$$\int \frac{\mathrm{d}u}{u^2}
= -\frac 1 2 u^{-1}$$
OpenStudy (anonymous):
Okay, let's substitute \(u = \sin x\).
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OpenStudy (anonymous):
The answer is $$-\frac{1}{2 \sin x}$$
OpenStudy (anonymous):
thanks
OpenStudy (anonymous):
another one please
OpenStudy (anonymous):
???
OpenStudy (anonymous):
Sure.
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OpenStudy (anonymous):
integral
sinx(2cscx+sinx)dx
OpenStudy (anonymous):
$$\int (\sin x)(2 \csc x + \sin x) \, \mathrm{d}x$$
OpenStudy (anonymous):
\(\csc x = \frac 1 {\sin x}\).
OpenStudy (anonymous):
yes
OpenStudy (anonymous):
ok
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OpenStudy (anonymous):
1+sin^2x
OpenStudy (anonymous):
Kind of. You forgot the 2.
$$\int 2 + \sin^2 x \, \mathrm{d}x$$.
OpenStudy (anonymous):
ok
OpenStudy (anonymous):
the last one?
OpenStudy (anonymous):
???
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OpenStudy (anonymous):
Have you got the answer to the previous integral?
OpenStudy (anonymous):
no
OpenStudy (anonymous):
x+...?
OpenStudy (anonymous):
?????????????
OpenStudy (raden):
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