" 11."cos^(4)2x

Find the extreme values of 11 cos^(2) x+ 15 sin x cos x- 9 sin^(2) x .

Prove that, "cos" pi/11 "cos" (2pi)/11 "cos" (3pi)/11 "cos" (4pi)/11 "cos" (5pi)/11 = 1/32

5. if the expression cos^2(pi/11)+cos^2((2pi)/11)+cos^2((3pi)/11)+cos^2((4pi)/11)+cos^2((5pi)/11) has the value equal to p/q in it lowest from ; then find (p+q)

If the expression cos^2(pi/11)+cos^2((2pi)/11)+cos^2((3pi)/11)+cos^2((4pi)/11)+cos^2((5pi)/11) has the value equal to p/q in it lowest from ; then find (p+q)

int_-1^1 x^11 cos^4 x dx is equal to :

Evaluate: int(cos2x sin4xdx)/(cos^(4)x(1+cos^(2)2x))

If sin^(4)2x+cos^(4)2x=sin2x*cos2x then x=

Let cos^(4)x=a cos(4x)+b cos(2x)+c where a,b,c are constants then

If cos x=t a n x , then which of the following is true? (a) 1/(sinx)+cos^4x=1 (b) 1/(sinx)+cos^4x=2 (c) cos^(54)x+cos^2x=1 (d) cos^4x+cos^2x=2