Giải phương trình \(\sqrt 2 \left( {\sin x + \cos x} \right) - 1 = \sin x\cos x.\)
A.\(S = \left\{ {\alpha - \frac{\pi }{4} + k\pi ;\frac{{3\pi }}{4} - \alpha + k\pi } \right\}\)
B.\(S = \left\{ {\alpha - \frac{\pi }{4} + k2\pi ;\frac{{3\pi }}{4} - \alpha + k2\pi } \right\}\)
C.\(S = \left\{ {\alpha - \frac{\pi }{4} + k2\pi ;\alpha - \frac{{3\pi }}{4} + k2\pi } \right\}\)
D.\(S = \left\{ {\alpha - \frac{\pi }{4} + k\pi ;\alpha - \frac{{3\pi }}{4} + k\pi } \right\}\)