4.9-1/化简:[cos(a+15度)]^2+[sin(a-15度)]^2+[sin(a+180度)]*[cos(a-
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4.9-1/化简:[cos(a+15度)]^2+[sin(a-15度)]^2+[sin(a+180度)]*[cos(a-180度)].
做出来都是1+sin(2a)
做出来都是1+sin(2a)
[cos(a+15度)]^2+[sin(a-15度)]^2+[sin(a+180度)]*[cos(a-180度)]
=[cos(2a+30)+1]/2+[1-cos(2a-30)]/2+1/2sin2a
=1+[cos(2a+30)-cos(2a-30)]/2+1/2sin2a
=1-2sin2a*sin30/2+1/2sin2a
=1
=[cos(2a+30)+1]/2+[1-cos(2a-30)]/2+1/2sin2a
=1+[cos(2a+30)-cos(2a-30)]/2+1/2sin2a
=1-2sin2a*sin30/2+1/2sin2a
=1
4.9-1/化简:[cos(a+15度)]^2+[sin(a-15度)]^2+[sin(a+180度)]*[cos(a-
化简:[cos(a+15度)]^2+[sin(a-15度)]^2+[sin(a+180度)]*[cos(a-180度)]
化简cos^2(a+15)+sin^2(a-15))+sin(a+180)cos(a-180)
化简~cos^2(a+15)+sin^2(a-15)+sin(a+180)cos(a-180)
sin(a+105度)cos(a-15度)-cos(a+105度)sin(a-15度)
化简Sin A + Sin 2A / 1+cos A +
化简sin(a-15度)cos(a+15度)+cos(a-15度)sin(a+15度)
化简:1,sin(pai/4-x)sin(pai/4+x) 2,cosA+cos(120度-A)+cos(120度+A)
证明Cos^A-Sin^A=1-2Sin^A=2Cos^A-1=cos^a-sin^a
化简:sin 2a/(1+cos 2a) * cos a/(1+cos a)
化简:sin(-a)cos(2π+a)sin(-a-π)
化简 1-sin^4a-cos^4a/cos^2a-cos^4a