已知sin(π/4+2a)sin(π/4-2a)=1/4,a∈（π/4,π/2)求2sin方a+tana-cota-1

已知sin(π/4+2a)sin(π/4-2a)=1/4,a∈（π/4,π/2)求2sin方a+tana-cota-1 已知tana+cota=5/2,求cos2a和sin(2a+π/4) 已知sin(a+π/4）=√6/3,求tana+cota的值 已知cosa=1/4,求sin(2π+a)cos(-π+a)/cos(-a)tana 数学题在线解答已知tana+cota=5/2,a∈（π/4,π/2),求cos2a和sin(2a+π/4)的值 已知(1+tana)/(1-tana)=3+2√2,求cos(π-a)方+sin(π+a)cos(π-a)+sin(a- 已知sin(a/2)=4/5,a∈(π,2π),求sina,cosa,tana. 已知sin(a/2)=4/5,a∈(π,2π),求sina,cosa,tana 已知函数f(x)=(1+1/tanx)sin^2-2sin(x+π/4)sin(x-π/4).求tana=2时,f(a) 已知tana=2 求sin²a-sina*cos(a-4π)+2的值 tanA=1/ tanA=sinA/ cotA=cosA/ sin^2A+cos^2A= 若sina+f(a)=2/3,f(a)=sin(a+π/2),求(√2sin(2a-π/4)+1)/(1+tana)的值