`cos^6pi/9-33tan^4pi/9+27tan^2pi/9` is equal to 0 (b) `sqrt(3)` (c) 3 (d) 9

tan^(6)((pi)/(9))-33tan^(4)((pi)/(9))+27tan^(2)((pi)/(9)) is equal to (a)0 (b) sqrt(3)(c)3(d)9

9sec^(2)A-9tan^(2)A is equal to (a)1(b)9(c)8 (d) 0

The numerical value of tan((pi)/(3))+2tan((2 pi)/(3))+4tan((4 pi)/(3))+8tan((8 pi)/(3)) is equal to (A)-5sqrt(3)(B)-(5)/(sqrt(3))(C)5sqrt(3)(D)(5)/(sqrt(3))

3tan^(6)((pi)/(18))-27tan^(4)((pi)/(18))+33tan^(2)((pi)/(18)) equals -

cos(2001)pi+cot(2001)(pi)/(2)+sec(2001)(pi)/(3)+tan(2001)(pi)/(4)+csc(2001)(pi)/(6) equal to 0(b)1(c)-2(d) not defined

If int_(0)^(a)(dx)/(sqrt(x+a)+sqrt(x))=int_(0)^((pi)/(3))(2tan theta)/(sin2 theta)d theta, then value of a' is a equal to (a>0)(3)/(4)( b) (pi)/(4)(c)(3 pi)/(4) (d) (9)/(16)

If alpha = cos^(-1)((3)/(5)), beta = tan ^(-1)((1)/(3)) , where 0 lt alpha, beta lt (pi)/(2) , then alpha - beta is equal to (A) tan ^(-1)((9)/( 5sqrt(10))) (B) cos ^(-1)((9)/( 5sqrt(10))) (C) tan^(-1)((9)/(14)) (D) sin ^(-1)((9)/(5 sqrt(10)))

cos (- (9 pi) / (4)) =