化简lg(cosx tanx+cosx)+lg[根号2cos(x-π/4)]-lg(1+2sinxcosx)已知0
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化简lg(cosx tanx+cosx)+lg[根号2cos(x-π/4)]-lg(1+2sinxcosx)已知0
化简lg(cosx tanx+cosx)+lg[根号2cos(x-π/4)]-lg(1+2sinxcosx)
已知0
化简lg(cosx tanx+cosx)+lg[根号2cos(x-π/4)]-lg(1+2sinxcosx)已知0
lg(cosx tanx+cosx)+lg[根号2cos(x-π/4)]-lg(1+2sinxcosx)
=lg(cosx ×sinx/cos+cosx)+lg[根号2cos(x-π/4)]-lg(sin²x+cos²x+2sinxcosx)
=lg(sinx+cosx)+lg[根号2cos(x-π/4)]-lg(sinx+cosx)²
=lg(sinx+cosx)+lg[根号2cosxcosπ/4+sinxsinπ/4)]-lg(sinx+cosx)²
=lg(sinx+cosx)+lg[cosx+sinx]-lg(sinx+cosx)²
=lg(sinx+cosx)(cosx+sinx)-lg(sinx+cosx)²
=lg[(sinx+cos)²/(sinx+cosx)²]
=lg1
=0