If \(\underline{x+y=1}\) and \(\underline{x}\) minus \(y\) equals the product of the square root of 2 and the sine of theta, what is \(x\) times \(y\)?

W) Cosine of 2 theta

X) Sine of 2 theta

Y) One-fourth the cosine of 2 theta

Z) One-fourth the sine of 2 theta
Y) ONE-FOURTH THE COSINE OF 2 THETA