" 9.(i) "cos x^(@)

If 5 (tan ^(2) x - cos ^(2) x ) = 2 cos 2x +9 , then the value of cos 4 x is

Solve for x : (i) cos((x)/(2) + 10^(@)) = (sqrt(3))/(2) (ii) sin^(2) 60^(@) + cos^(2)(3x - 9^(@)) = 1

Number of solution (s) of the equation (sin x)/( cos 3 x) +( sin 3 x )/( co 9 x) + ( sin 9 x )/( cos 27 x) = 0 in the interval (0, (pi)/( 4)) is

(i) int(sinx)/(sqrt(4+ cos^(2) x)) dx " "(ii) int(x^(2))/(sqrt(9+x^(6)))dx

(i) int(sinx)/(sqrt(4+ cos^(2) x)) dx " "(ii) int(x^(2))/(sqrt(9+x^(6)))dx

If sum _(i=1) ^(9) (x _(i) - 5) = 9 and sum_(i =1) ^(9) (x _(i) - 5) ^(2) = 45, then the standard deviation of the 9 terms x _(1), x _(2),....,x _(9) is

(sin theta+i cos theta)^(9) =

((sin 7x + sin 5x ) +(sin 9x + sin 3x))/( (cos 7x + cos 5x ) + (cos 9x + cos 3x ))= tan 6x

((sin 7x + sin 5x ) +(sin 9x + sin 3x))/( (cos 7x + cos 5x ) + (cos 9x + cos 3x ))= tan 6x