" (xi) "cos^(4)x+sin^(4)x=(1)/(2)(1+2a^(2)-a^(4))=

cos^(4)x+sin^(4)x=(1)/(2)(1+2a^(2)-a^(4)) wherea =sin x+cos x

Prove that, cos^(4)x + sin^(4)x = 1/2 (1 + 2 a^(2) - a^(4)) Where a = sin x + cos x

If f(x)=(4cos^(4)x-2cos^(2)x-(1)/(2)cos4x+2sin^(2)x-x^(9))^((1)/(9)) then the value of f(f(2)) is equal to

sin^(4)x+cos^(4)x=1-2sin^(2)x cos^(2)x

lim_(x to oo)(sin^(4)x-sin^(2)x+1)/(cos^(4)x-cos^(2)x+1) is equal to

lim_(xtooo) (sin^(4)x-sin^(2)x+1)/(cos^(4)x-cos^(2)x+1) is equal to

If (cos ^ (4) x) / (cos ^ (2) y) + (sin ^ (4) x) / (sin ^ (2) y) = 1 then prove that (cos ^ (4) y) / (cos ^ (2) x) + (sin ^ (4) y) / (sin ^ (2) x) = 1

prove that: sin ^ (4) x + cos ^ (4) x = 1- (1) / (2) sin ^ (2) 2x

If (cos^(4)x)/(cos^(2)y)+(sin^(4)x)/(sin^(2)y)=1 , then (cos^(4)y)/(cos^(2)x)+(sin^(4)y)/(sin^(2)y) equal :

(lim)_(x rarr)(sin^(4)x-sin^(2)x+1)/(cos^(4)x-cos^(2)x+1) is equal to (a) 0( b) 1 (c) (1)/(3)(d)(1)/(2)