Question

Verify the identity. cot (x-π/2) = -tan x

Answer 1

depends on what you get to use
the cofunction identity tells you \[\cot(\frac{\pi}{2}-x)=\tan(x)\] and cotangent is an odd function so \[\cos(x-\frac{\pi}{2})=-\tan(x)\]

Answer 2

I don't get it.

Answer 3

satellite73 explained it already, cotangent is an odd function so,
\[\cot(-y)=-\tan(y)\]

Answer 4

@satellite73 sorry here you missed the cot and wrote cos

<< and cotangent is an odd function so
cos(x−π2)=−tan(x) >>

- this above wann being cot(x-pi/2)=-tanx

Answer 5

so cot(π/2-x) = tanx?

Answer 6

yes

Answer 7

that is a "cofunction" identity
like \[\sin(\frac{\pi}{2}-x)=\cos(x)\] and \[\csc(\frac{\pi}{2}-x)=\sec(x)\] if you draw a right triangle you will see why