Question 1180194
is cos x = 0.25, find sin x 

i have looked up tutorials but i am a bit confused.
<pre>{{{matrix(1,9, cos (x), "=", .25, "=", 1/4, "=", A/H, "=", x/r)}}}
{{{matrix(4,3, y^2, "=", r^2 - x^2, y^2, "=", 4^2 - 1^2, y, "=", sqrt(16 - 1), y, "=", sqrt(15))}}}
{{{highlight_green(matrix(1,7, sin (x), "=", O/H, "=", y/r, "=", highlight(sqrt(15)/4)))}}}