(sec A)/(cA)=(s)/(1-)

(1+sec A)/(sec A)=(sin^(2)A)/(1-cos A)

(1)/(sec A)+(sec A)/(sec A)

((sin 2A)/(sec A -1))((sec 2A)/(sec 2A+1))=

((sin2A)/(sec A-1))((sec2A)/(sec2A+1))=

(sec8A-1)/(sec4A-1)=?

Solve,(sec^(-1))(x)/(a)-(sec^(-1))(x)/(b)=sec^(-1)b-sec^(-1)a

If a,b,c are in A.P. prove that: (i) (ab)^(-1),(ca)^(-1) and (bc)^(-1) are also in A.P. (ii) (ab+ac)/(bc),(bc+ca)/(ca),(ca+cb)/(ab) are also in A.P.

Suppose S_(a)(x)=sec^(-1)((x)/(a))+sec^(-1)(a) for a!=0 .If S_(a)(x)=S_(b)(x) for a!=b then x=