Integration using substitution, integral of sin(x)/cos(x), Reddit r/askmath

[mokouf]

The funny moment:
5:20
ln|sex
-> ln|secx| + C

[_Exen_]

u sub is a little hard to understand at first but when you get it, it’s one of the most useful integration technics you can learn

[pabloduchen]

5:18 Now I finally know what the absolute value of sex is 😂

[ZipplyZane]

Seems weird they didn't show the steps of the t-substitution to make it clear.

[shivasenthil.a-a]

Can you integrate this simple thing?(Definite integration):
Integral 0 to π/2 secx/(2sin²x) dx

[Ynook]

I know it's kind of long to write, especially if you have multiple inverse functions, but I prefer to write them as arcsin, arccos and so on. No confusion this way.

[dannyyeung]

Can you do this integration by substituting t=sec(x)?

[kavinesh_the_legend]

I solved it without using pen and paper

[nobodyspecial]

Can anyone please explain why specifying the modulus of cosx is necessary?