Integral of cos^3 x

How to integrate cos^3 x.

[mr.mockidocki]

Right now i'm sitting at 4:50 am, and this guy is my hero, but there are 3 houres left to go to university))
Briefly speaking, Thanks a lot!

[marcochan]

From the second step it can be
in cos x (1-sin^2x) dx
=in 1-sin^2x d sinx
= in 1 d sinx - in sin^2x d sinx
=sinx - sin^3x / 3 +C

[angelrojael]

Thanks a lot for the simple explanation

[shouryathakur]

But you can use this formula:

3cos x - cos 3x/4

[loujc]

For all these trig integrals you could maybe use De Moivre’s theorem?

[Lofimania]

I think your answer is wrong by my book answer sheet

[caligulaninkatili]

Thx please don't stop to sharing math

[gulafshamansoori]

Sir cos3x ka pratham sidhdant ka awkalaj

[VishalKumar-kvqi]

Sawal nahin aati hai to Lagate Kyon ho be
Galat Sawal mat lagaya karo

[sujaljogu]

You can do the same by using the formula of cos3x the answer will be same

[siphilipe]

Here is another one who does not beg people to subscribe. And I already did add mine.

[belmokhtarbentadj]

If you do intégration by part you have another résultat
Let u=cos^2(x) du=2*cosx*sinx
dv=cosx v= sinx
I= u*v - int(v*du)
I= sinx*cos^2(x) - 2/3* sin^3(x) + c