urgent ..

formula for sin^-1X + sin^-1Y , sin^-1X -sin^-1Y

cos^-1X + cos^-1Y

cos^-1X - cos^-1Y

prove: tan inverse [ cos x / (1+sin x)] = pie /4 - (x/2)

show that tan(1/2 sin-1 3/4) = 4-root7/3

prove that :

tan [pi/4 + 1/2 cos^-1 a/b] + tan[pi/4 - 1/2cos^-1 a/b] = 2b/a

find the value of x : sin^-1x + sin^-1(1-x) = cos^-1x

formula of 1-sinx

Show that tan(1/2sin^-13/4) = (4-Squareroot of 7)/ 3

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

cos^-1(x) + sin^-1(x/2)=pi/6

find x.

Prove that :

tan^-1(1/4) + tan-1(2/9) = 1/2 Cos^-1 (3/5)

if cos^-1x + cos^-1y + cos^-1z = pi

prove that x² + y² + z² +2xyz = 1

find the greatest and least values:(sin^-1x)²+(cos^-1x)²

prove that tan ^-1(1) + tan^-1(2) + tan^-1(3) = pie.