If `a_(1), a_(2), a_(3),...., a_(n)` is an A.P. with common difference d, then prove that
`tan[tan^(-1) ((d)/(1 + a_(1) a_(2))) + tan^(-1) ((d)/(1 + a_(2) a_(3))) + ...+ tan^(-1) ((d)/(1 + a_( - 1)a_(n)))] = ((n -1)d)/(1 + a_(1) a_(n))`

If a_(1),a_(2),a_(3),a_(n) is an A.P.with common difference d, then prove that tan[tan^(-1)((d)/(1+a_(1)a_(2)))+tan^(-1)((d)/(1+a_(2)a_(3)))+tan^(-1)((d)/(1+a_(n-1)a_(n)))]=((n-1)d)/(1+a_(1)a_(n))

If a_(1),a_(2),a_(3),….a_(n) is a.p with common difference d then tan{tan^(-1)((d)/(1+a_(1)a_(2)))+tan^(-1)((d)/(1+a_(2)a_(3))) +..+ tan^(-1)((d)/(1+a_(n-1)a_(n)))} is equal to

If a_(1),a_(2),a_(3),...a_(n) are in arithmetic progression with common difference d, then evaluate the following expression: tan{tan^(-1)((d)/(1+a_(1)a_(2)))+tan^(-1)((d)/(1+a^(2)a_(3)))+tan^(-1)((d)/(1+a_(3)a_(4)))+...+tan^(-1)((d)/(1+a_(n-1)a_(n)))}

If a_(1), a_(2), a_(3) are in arithmetic progression and d is the common diference, then tan^(-1)((d)/(1+a_(1)a_(2)))+tan^(-1)((d)/(1+a_(2)a_(3)))=

If a_(1), a_(2), …..,a_(n) are in A.P. with common difference d ne 0, then the sum of the series sin d[sec a_(1)sec a_(2) +..... sec a_(n-1) sec a_(n)] is

If a_(1),a-(2),a_(3),………….a_(n) are in A.P. with common differecne d, prove that sin [cosec a_(1)coseca_(2)+cosec a_(2)cosec a_(3)+………….+cosec a_(n-1)cosec a_(n)]=cota_(1)-cota_(n) .

If a_(0),a_(1),a_(3),a_(4)......... are in AP with common difference d where d!=0,1,-1, then the det[[a_(1)a_(2),a_(1),a_(0)a_(2)a_(3),a_(2),a_(1)a_(3)a_(4),a_(3),a_(2)]] is

If a_(1),a_(2),a_(3),,a_(n) are an A.P.of non-zero terms, prove that _(1)(1)/(a_(1)a_(2))+(1)/(a_(2)a_(3))++(1)/(a_(n-1)a_(n))=(n-1)/(a_(1)a_(n))