" 1."(-(2)/(3))^(5)" an "4 pi" ? "

sin ((pi) / (5)) sin ((2 pi) / (5)) sin ((3 pi) / (5)) sin ((4 pi) / (5)) =

The principal value of sin^(-1)(sin((2 pi)/(3))) is (a)-(2 pi)/(3) (b) (2 pi)/(3) (c) (4 pi)/(3) (d) (5 pi)/(3) (e) none of these

Let theta = tan^(-1) ( tan . (5pi)/4) " and " phi = tan^(-1) ( - tan . (2pi)/3) then

Let theta = tan^(-1) ( tan . (5pi)/4) " and " phi = tan^(-1) ( - tan . (2pi)/3) then

Let theta = tan^(-1) ( tan . (5pi)/4) " and " phi = tan^(-1) ( - tan . (2pi)/3) then

sin ^ (2) ((2 pi) / (3)) + cos ^ (2) ((5 pi) / (6)) - tan ^ (2) ((3 pi) / (4))

Prove that: sin^(-1)(-(4)/(5))=tan^(-1)(-(4)/(3))=co^(-1)(-(3)/(5))-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)

cos ^ (2) (3 (pi) / (5)) * cos ^ (2) (4 (pi) / (5))

cos ^(2) (3 pi)/(5)+cos ^(2) (4 pi)/(5)=