[" 10.If "pi<=x<=2 pi," then "cos^(-1)(cos x)" is equal to "],[[" (a) "x," (b) "-x],[" (c) "2 pi+x," (d) "2 pi-x]]

The value of cos""(pi)/(7)+cos""(2pi)/(7)cos""(3pi)/(7)+cos""(4pi)/(7)+cos""(5pi)/(7)+cos""(6pi)/(7)+cos""(7pi)/(7) is

The value of sin""(pi)/(14).sin""(3pi)/(14).sin""(5pi)/(14).sin""(7pi)/(14).sin""(9pi)/(14).sin""(11pi)/(14).sin""(13pi)/(14) is

Prove that (i) " tan"^(2) .(pi)/(3) + 2cos^(2) .(pi)/(4)+ 3 sec^(2).(pi)/(6)+ 4 cos^(2).(pi)/(2)=8 (ii) " sin ".(pi)/(6) " cos 0 + sin ".(pi)/(4) " cos " .(pi)(4) + " sin " .(pi)/(3) "cos " .(pi)/(6) =(7)/(4) (iii) " 4sin " (pi)/(6) " sin"^(2) (pi)/(3) + 3 " cos " .(pi)/(3) " tan ".(pi)/(4) = " cosec"^(2).(pi)/(2)=4

The value of cos""(pi)/(11)+cos""(3pi)/(11)+cos""(5pi)/(11)+cos""(7pi)/(11)+cos""(9pi)/(11), is

The value of cos""(pi)/(11)+cos""(3pi)/(11)+cos""(5pi)/(11)+cos""(7pi)/(11)+cos""(9pi)/(11), is

The value of cos""(pi)/(11)+cos""(3pi)/(11)+cos""(5pi)/(11)+cos""(7pi)/(11)+cos""(9pi)/(11), is

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 value of the integral int_-pi^pi (1-x^2)sinxcos^2xdx is (A) 0 (B) pi-pi^3/3 (C) 2pi-pi^3 (D) pi/2-2pi^3

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)

If cosec . (pi)/(32)+ cosec. (pi)/(16)+ cosec. (pi)/(8)+ cosec. (pi)/(4)+ cosec. (pi)/(2)= cot. (pi)/(k) , then the value of k is