I think that my integral is wrong

[Robert Mak]

Integral of ((Tan x)^6)dx

i think that the solution is:

(1/5)(tan x)^5 + (1/3)(tan x)^3 - (2/3)(tan x)^3 + tan x - x + c

but if i derivate this solution it lead me to that:


(tan x)^4((tan x)^2 + 2)

?

 

[^_^physicist]

Yes, your integral is incorrect; however, try expanding the expression and then integrating.

 

[Dick]

I think your integral is correct. It must be the differentiation that is causing the problem. But no one can tell you why until you show your work.

 

[cristo]

It looks correct to me, also (although, why you haven't collected those terms in tan^3x, I don't know!)

 

[Gib Z]

I think he might forgetting to use the Chain Rule.

 

[Robert Mak]

Thanks people; i did a mistake of signs lol.