Question

int secx dx? what kind of magic should I do? need a step by step solution ^^

Answer 1

\[\large \int \sec x dx\] \[\large \int \sec x \times \frac{\sec x + \tan x}{\sec x + \tan x} dx\]

Answer 2

Write it as:
\[\int\limits\frac{secx}{1}dx \]
Then multiple top and bottom by \(secx+tanx\) then u-sub.

Answer 3

you will get \[\large \int \frac{(\sec^2 x + \sec x \tan x)dx}{\sec x + \tan x}\] you get it so far right @GuilhermCosta ??

Answer 4

yep

Answer 5

I just don't know what to 'u-sub' =/

Answer 6

let \(u=secx+tanx\)

Answer 7

now if i let u = \(\sec x + \tan x\)

du = \((\sec x \tan x + \sec^2 x)dx\)

which is our numerator...therefore it becomes \[\large \int \frac{du}{u}\]

Answer 8

*-* thank you so much!

Answer 9

we can't mark more than one good answer anymore? o.O

Answer 10

yeah..makes you have to choose medal wisely

Answer 11

apparently some people were abusing the multiple medal system and devaluing the medals

Answer 12

=/
thank you 2 anyway ^^