Question

verify the identity, tan(x+pi/2)=-cot x

Answer 1

\[\huge\rm tan(x + y ) = \frac{ \tan x + \tan y }{ 1- \tan x \times \tan y }\]
use this formula

Answer 2

pi/2 = 90 degree
what is cos and sin value at 90 degree ?

Answer 3

I'm not really sure.

Answer 4

nah forget
that's wrong

Answer 5

*wait 4 someone else*

Answer 6

Sure, thanks.

Answer 7

\[\tan(x+\pi/2)=\frac{ \sin (x+\pi/2) }{ \cos(x+\pi/2) }=\frac{ sinx \cos \pi/2+\cos x \sin \pi/2 }{ \cos x \cos \pi/2-sinx \sin \pi/2 }\]

Answer 8

\[\sin \pi/2=1 , \cos \pi/2 =0\]

Answer 9

That verifies the identity?

Answer 10

yep

Answer 11

Thanks.