T
thien0526


minh k bik ghi kieu hieu toan hoc. neu ban nao bik thi sua lai jup mih nha, san giai jup mih luon. tks trc.
cac pt nay cac ban jai ra nghiem roi doi chieu jup mih lun nha. hih nhu la pt nghiem nguyen hay s ay
a)(sinx.cot3x)/cos5x = 1
b)cos2x - tan^2 x = (cos^2 x-cos^3 x -1)/cos^2 x
c)tan^4 x+1= [(2-sin^2 2x)sin3x)] /cos^4 x
d)(sinx+sin2x+sin3x)/(cosx+cos2x+cos3x)=\sqrt[2]{3}
cac pt nay cac ban jai ra nghiem roi doi chieu jup mih lun nha. hih nhu la pt nghiem nguyen hay s ay
a)(sinx.cot3x)/cos5x = 1
b)cos2x - tan^2 x = (cos^2 x-cos^3 x -1)/cos^2 x
c)tan^4 x+1= [(2-sin^2 2x)sin3x)] /cos^4 x
d)(sinx+sin2x+sin3x)/(cosx+cos2x+cos3x)=\sqrt[2]{3}