Math
posted by Anonymous on .
Show that
sinx = (square root of) 1  cos^2x
is not an identity

All we need is one counterexample to show it is not an identity.
let x = 210º
LS = sin 210 = 1/2
RS = √(1 cos^2 (210º))
= √(.25)
= 1/2
So there!