Nếu \(\sin x + \cos x = \frac{1}{2}\) thì \(\sin 2...

Câu hỏi: Nếu \(\sin x + \cos x = \frac{1}{2}\) thì \(\sin 2x\) bằng ?

A. \( - \frac{3}{4}\)

B. \(\frac{{\sqrt 2 }}{2}\)

C. \(\frac{3}{8}\)

D. \(\frac{3}{4}\)