# mathematics

posted by
**edward**
.

1.)Sin^-1(x)+Sin^-1(y)+Sin^-1(z)= pie

Prove that

X.root(1-y^2)+y.root(1-x^2)+z.root(1-z^2)=2xyz

2.)tan^-1(yz/xr)+tan^-1(zx/yr)+tan^-1(xy/zr)=pie/4

Prove that

x^2+y^2+z^2=r^2

Tomorrow is my exam.please give me answer as soon as possible.