Calculus Question!-doubt(a simple one)

\int 2(cos2x)/(2-2sin^22x) \delta x

16 Answers

1
Rohan Ghosh ·

=2cos2x/2cos22x

=(1/cos2x)dx

take tanx=t => sec2xdx=dt

=>(1+t2)dx=dt

then cos2x=1-t2/(1+t2)

so it reduces to

dt/(1-t2)

=1/2(dt/1+t +dt/(1-t))

1
sriraghav ·

Thank U!!!!!!!!!!!!!!!!!!!!!! : )

24
eureka123 ·

ya good work again by rohan.............................always use universal substitution when nothing strikes.............it always works.........[6]

1357
Manish Shankar ·

hmm
that conversions of 2-2sin22x=2cos22x was good
but that is not required here

just put sin2x=t

1
KR ·

y 4 all that steps :
u can do it easily::

\int 2(cos2x)/2(cos^{2}2x)\delta x =\int 1/cos2x \delta x =\int sec2x dx =1/2(log\left|sec2x+tan2x \right|)

think its correct

1
KR ·

{:-(|)

1
sriraghav ·

Sorry in denominator it is not 2-2sin2x , but 2 - sin2x

1
sriraghav ·

Some one answer please!!It luks bit difficult

1
°ღ•๓яυΠ·

u can wrte d numerator as 8-4sin^2x -6

so ur int reduces to

4 - 6/(2-sin^2x)
nw d second one is easy write tan(x/2)=t
or
multiply n divide by sec^2x
then ur second part bcums

6sec^2x/(2sec^2x-tan^2x)
write tanx=t

u r done ;)

1357
Manish Shankar ·

is it sin22x or sin2x

1
°ღ•๓яυΠ·

itz sin^2x

1
sriraghav ·

sir it is sin22x

1
°ღ•๓яυΠ·

yeh toh aur bhi easy hai
put sin2x as t bas ho gaya

1
sriraghav ·

but in numerator u will get (-2 * sin 2x * cos 2x * 2), can u post the soln. pls

1
°ღ•๓яυΠ·

arey i said put sin2x as t n not sin22x

1
sriraghav ·

Ohh!! Sorry.. i didnt read it fully... Thank u..... (easy one) hehe :)sorry for wasting all of ur time....

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