已知(4sin a-2cos a)/(5cos a +3sin a)=6/11,求cos^4 a-sin^4 a
已知(4sin a-2cos a)/(5cos a +3sin a)=6/11,求cos^4 a-sin^4 a
已知sin a =2cos a .求sin a -4cos a ╱5sin a +2cos a的
已知sin a-2cos a=0 求4sin^2 a-3sin a x cos a-5cos^2 a的值
已知tan a=-1/3,求4sin a-2cos a/5cos a+3sin a=
已知tan a=2,求:(4*sin a-2*cos a)/(5*sin a+3*cos a)的值
已知a(-0,兀且2SIN A-SIN ACOS A-3COS A=0求SIN(+兀/4)/SIN 2A+COS 2A+
已知a是锐角且cos^4a-sin^4a=3/5,求(sin^2a+3sinacosa-cos^2a)/(2sin^2a
已知:tan A=2,求:(2sin A-2cos A)/(4sin A-9cos A) 、
已知tan a=2 求(2sin a-3cos a)/(4sin a-9cos a)
已知a属于(0,π/2),且2sin^2 a-sin a cos a-3cos^2 a=0,求SIN(a+兀/4)/SI
急::已知sin(3π+a)=2cos(a-4π),求(5sin(π/2+a)+cos(π/2-a))/(2cos(π+
已知sin(a-3π)=2cos(a-4π),求(sin(π-a)+5cos((3π/2)-a))/(2sin(3π/2