If `e^((cos^2x+cos^4+cos^x……)log3)` satisfies the equation `t^2-8t-9=0` then the value of `tnx,(0ltxltpi/2)` is (A) `sqrt(3)` (B) `sqrt(2)` (C) 1 (D) `1/sqrt(2)`

If e^(( cos^2 x + cos^4x+ cos ^6 x + ……..oo ) log_e 2) satisfies the equation t^2 - 9t + 8=0 , then the value of ( 2 sin x)/( sin x + sqrt(3) cos x) ( 0 lt x lt (pi)/(2)) is

The value of cot70^(@)+4cos70^(@) is (a) (1)/(sqrt(3)) (b) sqrt(3)(c)2sqrt(3)(d)(1)/(2)

The value of cos (1110^@) is A. sqrt3//2 B. 1//2 C. 1//sqrt2 D. 1

Let cos^(-1)(x)+cos^(-1)(2x)+cos^(-1)(3x)be pi If x satisfies the equation ax^(3)+bx^(2)+cx-c_(1)=0, then the value of (b-a-c) is

If f(x)=int_0^sinx cos^-1t dt+int_0^cosx sin^-1t dt, 0ltxltpi/2 , then f(pi/4)= (A) 0 (B) pi/sqrt(2) (C) 1 (D) pi/(2sqrt(2))

The value of cos48cos12 (A) (sqrt(5)+3)/(8) (B) (3-sqrt(5))/(2) (C) (sqrt(5)+1)/(4) (D) (sqrt(5)-1)/(4)

The value of x in (0,(pi)/(2)) satisfying (sqrt(3)-1)/(sin x)+(sqrt(3)+1)/(cos x)=4sqrt(2) is / are

The solution for x of the equation int_(sqrt(2))^(x)(dt)/(t sqrt(t^(2)-1))=(pi)/(2) is: (A) 2(B)pi(C)(sqrt(3))/(2) (D) 2sqrt(2)

If (x,y) satisfy the equation 1+4x-x^(2)=sqrt(9(secy)^(2)+4(cos ecy)^(2)) then the value of xcoty is equal to