求值sin(9兀/4)+cos(2兀/3)+tan(5兀/4)

求值sin(9兀/4)+cos(2兀/3)+tan(5兀/4) 求值： 2(sin^6 θ+cos^6 θ)-3(sin^4 θ+cos^4 θ) 2sin²α-3sinαcosα+4 已知tanα=3 求值 求值:sin(26π/3)+cos(-17π/4)= 求值1.cos[arcsin(-4/5)-arctan(-3/4)]2.sin[1/2arcsin(-12/13)] 求值4sin^2a-3sinacosa-5cos^2a 已知cos2α=3/5,求值:cos^2α+sin^4α 求值：cos^2α-sin^2α 已知(tanα-3)(sinα+cosα+3)=0 求值(1) 4sinα+2cosα/5cosα+3sinα (2) sin²α+4cosα² 已知tana=1/2,sin^2α-3sinαcosa+4cos^2α求值 求值【sin(2π-α)sin(π+α)cos(-π-α)】/【sin(3π-α)-cos(π-α)】 高中三角函数化简求值化简：√2-sin^2+cos4 （根号下） cos(π/9)*cos(2π/9)*cos(3π/9)*cos(4π/9） 已知tanα=-1/2,求值1.(sinα+cosα)/(sinα-2cosα)2.(sin^2α-2sinαcosα-4cos^2α)/(3cos^2α-5sin^α)3.1+sin^2α-3sinαcosα sin(π+π/6)-cos(π+π/4)cos(-π/2)+1求值 求值sin(π/2)*sin(π/3)+2cos(-π/2)-根号3*tan(π/3) 求值,4-1/4sin^22a-sin^2a-cos^4a 求值:2sinπ/6+sin3π/2-2cosπ+2sinπ/3 求值:3/(sin^2 20°)-1/(cos^2 20°)+64sin^2 20°