cos((4x+9)/(5))

If (sin^(4)x)/(5)+(cos^(4)x)/(5)=(1)/(9), then which of the follwing is /are 'TRUE?

(1)/(3) cos((x)/(3)-4)+(7)/(7x+9)+e^((x)/(5)+3)

cos (4x + 5)

Prove : underset(xrarr0)"lim"(cos9x-cos7x)/(cos7x-cos5x)=(4)/(3)

Prove that : ([sin(7x)+sin(5x)]+[sin(9x)+sin(3x)])/([cos(7x)+cos(5x)]+[cos(9x)+cos(3x)])=tan(6x)

cos2x(cos x)/(2)-cos3x(cos(9x))/(2)=sin5x(sin(5x))/(2)

A point on the ellipse,4x^(2)+9y^(2)=36, where the normal is parallel to the line,4x-2y-5=0 is (A) ((8)/(5),-(9)/(5))(B)(-(9)/(5),(8)/(5))(C)((8)/(5),(9)/(5))(D)((9)/(5),(8)/(5))

Prove that cos 2xcos(x/2)-cos 3x cos((9x)/2)= sin5x sin((5x)/2) .

If 5(tan^(2)x-cos^(2)x)=2cos2x+9, then the value of cos4x is: (2)/(9)(2)-(7)/(9)(3)-(3)/(5)(4)(1)/(3)

Evaluate int (9cos x-sin x)/(4sin x+5cos x) dx