Question

Verify the identity.

cot ( x - pi /2) = -tan x

Answer 1

tan (pi / 2 - x) = cot x
Which means
cot (pi / 2 - x) = tan x since cot x = 1 / tan x
Also
tan (a - b) = -tan (b - a)
And cot (a - b) = -cot (b - a)

Answer 2

cot ( x - pi /2) = -tan x
LHS = cot ( x - pi /2) = -cot ( pi /2-x)=-tanx =RHS
Thus Proved

Answer 3

What does this mean you all lost me explain it please

Answer 4

tan (pi / 2 - x) = 1 / tan x = cot x
1 / tan (pi / 2 - x) = 1 / (1 / tan x)
cot (pi / 2 - x) = tan x

Next
tan (a - b) = tan (-(b - a)) = - tan (b - a)
1 / tan (a - b) = -1 / tan (b - a)
cot (a - b) = -cot (b - a)

Answer 5

Where do you get tan ( a-b)

Answer 6

Thats just a formula -.-

Answer 7

Much better
tan (-x) = -tan x

Answer 8

Ok so could tell me how to work it out

Answer 9

cot (x - pi / 2) = cot (-(pi / 2 - x)) = - cot (pi / 2 - x) = -tan x

Answer 10

Ok so thats it pretty much