Deriving equations involving sin and cos

[thezac11]

Homework Statement

I'm asked to derive equation(2) from equation(1).

equation(1): d=(tsin(2i))/((n^2-sin(i)^2)^1/2)

equation(2): n=sin(i)(((2tcos(i/d))^2+1)^1/2)

Homework Equations

The Attempt at a Solution

My attempts have got me nowhere, and I don't know how to even start to derive these equations. Any help would be greatly appreciated.

 

[tiny-tim]

hi thezac11!

(have a square-root: √ and try using the X² icon just above the Reply box )

start by squaring (1), and multiplying it by (n²-sin²(i))