设sin(a+π/2)=-1/4 且sin2a大于0 求sina tana
1个回答
由诱导公式:sin(a+π/2)=cosa=-1/4
sin2a=2sinacosa>0
则:sina
相关问题
sin^2a+sin2acosa-2cosa=1,a属于(0,π/2).求sina,tana.
已知sin(π/4+2a)*sin(π/4-2x)=1/4,a∈(π/4,π/2),求2sina^2+tana-1/(t
已知tana=2,求sina.sin(a-π/4)
已知sin²2a+sin2acosa-cos2a=1,a属于(0,π/2),求sina,tana
已知sin^2 2a+sin2acosa-cos2a=1,a E(0,π /2) 求sina tana
tana=2,a属于(π,3π/2) 求 sin(π+a)+2sin(3π/2+a)/cos(3π-a)+1 求sina
已知sin(a/2)=4/5,a∈(π,2π),求sina,cosa,tana
已知sin(π/4+2a)sin(π/4-2a)=1/4,a∈(π/4,π/2)求2sin方a+tana-cota-1
帮下 已知sin(π/4+2a) * sin(π/4-2a) =1/4 ,a∈(π/4,π/2,求2sin^a+tana
(1+tanA)/(1-tanA)=3+2√2,求cos^(π-A)+sin(π+A)cos(π-A)+2sin^(A-