# Math Help - Simple algebra Cant get kecturers answer :(

1. ## Simple algebra Cant get kecturers answer :(

$y = \sqrt {d^2 + l^2 + 2dl(1-(\phi^2 )}$

$
= d + l - (dl/d + l) \phi^2
$

2. What are you trying to do? Make which variable the subject?