i have 2 question -
1)if cos -1 (x/a)+cos-1(y/b)=d
prove that : x2/a2-2xy/ab-cosd+y2/b2=sin2d
2)solve tan(cos-1x)=sin(tan-1x)
3)tan-1x+tan-1y+tan-1z=pi/2
prove that xy+yz+zx =1
i have 2 question -
1)if cos -1 (x/a)+cos-1(y/b)=d
prove that : x2/a2-2xy/ab-cosd+y2/b2=sin2d
2)solve tan(cos-1x)=sin(tan-1x)
3)tan-1x+tan-1y+tan-1z=pi/2
prove that xy+yz+zx =1