Question

If \[\tan(\frac \pi 2 \sin a)=\cot(\frac \pi 2 \cos a)\] then cos a +sin a =

Answer 1

1

Answer 2

i got that too. but the answer is -1

Answer 3

no wait it says.. it could be 1 or -1

Answer 4

do you know how to get -1?

Answer 5

use tanx=tany implies x=n(pi)+y where n is integer.

Answer 6

u get cosa+sina=2n+1. when n=0 u get 1 and when n=-1 u get -1

Answer 7

which means we can get any no. upto both ways of infinity??

Answer 8

also use the fact that -rt(2)=<cosa+sina<=rt(2)
which narrows down n to ONLY 0 and -1

Answer 9

oh...okay..