Quick!!! secondary maths!!!

Question (a):

cot (丌/2 - y) = tan y = x
Hence (丌/2 - y) = arc cot x

arc tan x + arc cot x = y + (丌/2 - y)
arc tan x + arc cot x = y + 丌/2 - y
arc tan x + arc cot x = 丌/2


Question (b)
For-丌/2 <= y <- +丌/2

Cos (丌/2 - y) = sin y = x
Hence (丌/2 - y) = arc cos x
arc sin x + arc cos x = y + (丌/2 - y)
arc sin x + arc cos x = y + 丌/2 - y
arc sin x + arc cos x = 丌/2

2010-09-15 00:30:07 補充：
Question (a) continue:

arc tan x + arc cot x = 丌/2
arc tan x = 丌/2 - arc cot x