If` 4cos^(2)theta=3` then `theta`=----
1) `(pi)/(6),(5 pi)/(6)` 2) `(pi)/(4),(3 pi)/(4)` 3) `(pi)/(3),(2 pi)/(3)` 4) `+-(pi)/(2)`

((pi)/(4))+((2 pi)/(3))-((pi)/(6))

(pi)/(4)+(2 pi)/(3)-(pi)/(6)

(pi)/(4)-(3 pi)/(4)-(pi)/(6)+(pi)/(4)=

1+sinx + sin^2(x) + .... = 4+2sqrt3, 0ltxltpi, x!=pi, then x = 1) (pi)/(3), (pi)/(4) 2) (pi)/(4), (pi)/(6) 3) (2 pi)/(5), (pi)/(6) 4) (pi)/(3), (2 pi)/(3)

For 0 cos^(-1)(sin theta) is true when theta belongs to (a) ((pi)/(4),pi)(b)(pi,(3 pi)/(2))(c)((pi)/(4),(3 pi)/(4)) (d) ((3 pi)/(4),2 pi)

Given both theta and phi are acute angles and sin theta=(1)/(2),cos varphi=(1)/(3), then the value of theta+varphi belongs to (a)((pi)/(3),(pi)/(2)]( b) ((pi)/(2),(2 pi)/(3)] (c) ((2 pi)/(3),(5 pi)/(6)] (d) ((5 pi)/(6),pi]

The possible values of theta in (0, pi) such that sin (theta) + sin (4 theta) + sin (7 theta) = 0 are (1) (2 pi) / (9), (i) / (4 ), (4 pi) / (9), (pi) / (2), (3 pi) / (4), (8 pi) / (9) (2) (pi) / (4), (5 pi ) / (12), (pi) / (2), (2 pi) / (3), (3 pi) / (4), (8 pi) / (9) (3) (2 pi) / (9 pi) ), (pi) / (4), (pi) / (2), (2 pi) / (3), (3 pi) / (4), (35 pi) / (36) (4) (2 pi ) / (9), (pi) / (4), (pi) / (2), (2 pi) / (3), (3 pi) / (4), (8 pi) / (9)

The solution set of the equation 4s int h eta cos theta-2cos theta-2sqrt(3)s int_(h eta)+sqrt(3)=0 in the interval (0,2 pi) is {(3 pi)/(4),(7 pi)/(4)} (b) {(pi)/(3),(5 pi)/(3)}{(3 pi)/(4),pi,(pi)/(3)(5 pi)/(3)}(d){(pi)/(6),(5 pi)/(6),(11 pi)/(6)}

sin^(2)(pi)/(6)+cos^(2)(pi)/(3)-tan^(2)-(1)/(2)(pi)/(4)=-(1)/(2)

The solutions of the equation sin x+2sin2x+sin3x=cos x+3cos2x+cos3x in the interval 0<=x<=2 pi, are (pi)/(8),(5 pi)/(8),(2 pi)/(3)(b)(pi)/(8),(5 pi)/(8),(9 pi)/(8),(13 pi)/(8)(1 pi)/(3),(9 pi)/(3),(2 pi)/(3),(13 pi)/(8) (d) (pi)/(8),(5 pi)/(8),(9 pi)/(3),(4 pi)/(3),(4 pi)/(3),(9 pi)/(3),(2 pi)/(3),(13 pi)/(8)(d)