(1)f(x)＝2sinxcosx＋√3(2cos²x-1) ＝sin(2x)＋√3cos(2x)＝2×[1/2×sin(2x)＋√3/2×cos(2x)]
＝2×[sin(2x)cos60º＋sin60ºcos(2x)]＝2sin(2x＋60º)
(2)f(x)＝1/2cos²x－sinxcosx－1/2sin²x＝1/2(cos²x－sin²x)－1/2×2sinxcosx
＝1/2×[cos(2x)－sin(2x)]＝√2/2×[√2/2cos(2x)－√2/2sin(2x)]＝√2/2cos(2x＋45º)