Question

Verify the identity. cot(x-pi/2) =-tanx

Answer 1

i don't understand how to work out cot(x-pi/2)

Answer 2

cot(x-pi/2)= cos(x-pi/2)/sin(x-p/2) ; (1/ what the tan would have been)

cos(x-pi/2)=cosxcos (pi/2)+sinxsin(pi/2)
= cosx(0)+sin(1)
= sinx
if we simplify sin(x-pi/2) the same way, we are left with -cosx

So the first step simplifies to -sinx/cosx
Which is another way to write -(tanx)

Answer 3

thankyou!