原式=√2cos[π/2-(π/4-x)]+√6sin(x+π/4)
=√6sin(x+π/4)+√2cos(x+π/4)
=2√2[√3/2*sin(x+π/4)+1/2cos(x+π/4)]
=2√2[sin(x+π/4)cosπ/6+cos(x+π/4)sinπ/6]
=2√2sin(x+π/4+π/6)
=2√2sin(x+5π/12)