If ` x=cos 1 , y= cos1^(@)` then

I: If x= sin 1 , y= sin1^(@) then x lt y II : If x = cos 1 , y = cos 1^(@) " then " x lt y

If cos^(-1)x +cos^(-1)y +cos^(-1)z =3pi then x+y+z is :

If sec^(-1)x=cos ec^(-1)y, then cos^(-1)((1)/(x))=cos^(-1)((1)/(y))=

If (i) cos^(-1) x + cos^(-1) y + cos^(-1) z = pi , prove that : x^(2) +y^(2) +z^(2) + 2xyz = 1 (ii) If sin^(-1) x + sin^(-1) y + sin^(-1) z = pi/2 , prove that : x^(2) +y^(2) +z^(2) +2xyz = 1

If cos^(-1) x + cos^(-1) y + cos^(-1)z=pi , then a) x^2+y^2+z^2+xyz=0 b) x^2+y^2+z^2+2xyz=0 c) x^2+y^2+z^2+xyz=1 d) x^2+y^2+z^2+2xyz=1

If cos^(-1)x+cos^(-1)y=pi/2 then prove that cos^(-1)x=sin^(-1)y

If cos^(-1)x+cos^(-1)y=pi , then the value of (sin^(-1)x+sin^(-1)y) is -

x = cos1 ^ (@), y = cos1rArr

If cos^(-1) x + cos^(-1) y + cos^(-1) z = pi , then