Question

just so you know ....

Answer 1

\[\int\frac{1}{1+x^2}dx\ne tan^{-1}(1+x^2)\]
:)

Answer 2

twice on my homework I fauxpauxed that ....

Answer 3

typing and mathing just dont mix ;)

Answer 4

I did not know this, but it is probably in my table book.

Answer 5

i think its arctan(x)

if y=arctan(x)
then
tan(y)=x



sec^2(y)y'=1
y'=1/sec^2(y)

using the triangle we drew

we can write
y'=1/(x^2+1)

:)