Are these identities true for `0^(@) le A le 90^(@)` ? If not, for which values of A they are true ?
`cosec^(2)A - cot^(2)A = 1`

Are these identities true for 0^(@) le A le 90^(@) ? If not, for which values of A they are true ? sec^(2)A - tan^(2)A = 1

Are these identities true only for 0^(@) le A le 90 ^(@) ? If not ,for which other values of A they are true ? sec^(2) A-tan ^(2) A =1 " " cosec ^(2) A - cot ^(2) A=1

Find the values for tan 90^(@) ,cosec 90 ^(@) , sec 90 ^(@) and cot 90 ^(@)

For which value of an acute angle theta ,(i) ( cos theta )/( 1-sin theta ) +(cos theta )/( 1+sin theta ) =4 is true ? For which value of 0^(@) le theta le 90 ^(@) , above equation is not defined?

For 0 lt x le pi, sin h^(-1)(cot x) =