cos^4A-sin^4a 化简
1-sin^6a-cos^6a分之1-sin^4a-cos^4a 化简
化简1-sin^4a-cos^4a/1-sin^6a-cos^6a
化简 1-sin^4a-cos^4a/cos^2a-cos^4a
化简 sin^4a-cos^4b
化简(1-sin^6 a-cos^6 a)/(cos^2 a-cos^4 a)==
化简cos^4(a/2)-sin^4(a/2)=
sin(π/4-a) cos(a-π/4)化简
化简cos(pai/4 +a)+sin(pai/4 +a)
化简sin^4a-cos^4a/cos2a
化简:cos^4a-sin^4a=
Sin^4a+Sina*Cosa+Cos^2a化简
化简sin a+cos a