TỔNG HỢP LƯỢNG GIÁC HAY
1- sinx sin+ 2 x+sin3x+sin4x=cosx c+ os2x c+ os3x c+ os4x
2- 2cos3 (2cos 2x x+ =1) 1
3- os (cos2 1) 2(1 sinx)
sinx cos
c x x
x
− = + +
8cos 6 2 sin 2 3 2 os( 4 ) os2 16cos
2
x+ x+ c π − x c x= x
5- 2sin2x−sin 2x+sinx cos+ x− =1 0
6- 3 sin 2 (2cosx x+ + =1) 2 cos3x c+ os2x−3cosx
7- 2cos5 cos3x x+sinx=cos8x
8- 9sinx+6cosx−3sin 2x c+ os2x=8
9- 2cos 6x+2cos 4x− 3 os2c x=sin 2x+ 3
10- 2cos3 cos 3(1 sin 2 ) 2 3 os (22 )
4
x x+ + x = c x+π