[" 7.The expression "tan^(2)alpha+cot^(2)alpha" ,is "],[[" (a) ">=2," (b) "<=2],[" (c) ">=-2," (d) none of these "]]

The expression tan^2alpha+cot^2alpha is

If tan alpha+cot alpha=2 then

If tan alpha+cotalpha=2 , then tan^(20)alpha+cot^(20)alpha =

(tan^(2)alpha-sin^(2)alpha)*(cot^(2)alpha)/(sin^(2)alpha)=

If tan 2alpha = cot 2beta , then sec(alpha + beta) =

If tan alpha + cot alpha =2 , then tan^(20)alpha + cot^(20)alpha=

The expression (1 + sin 2 alpha )/( cos (2 alpha - 2pi) tan (alpha - (3pi)/(4 ))) -1/4 sin 2 alpha [ cot "" (alpha )/(2) + (alpha )/(2))] when simplified reduces to

The expression (tan alpha+tan beta)cot(alpha+beta)+(tan alpha-tan beta)cot(alpha-beta) is independent of both alpha and beta.