(8)quad sec^(2)2n=1-tan20

sec^(2)(20)-tan^(2)(20) is

sec^(2)A sec^(2)B-sec^(2)A tan^(2)B-tan^(2)A sec^(2)B+tan^(2)A tan^(2)B=

The value of (sec20^(@)+tan20^(@)-tan55^(@))is

What is the value of (tan^(2)25^(@))/(cosec^(2)65^(@))+(cot^(2)25^(@))/(sec^(2)65^(@))+tan20^(@)45^(@)tan70^(@) ?

Definite integration as the limit of a sum : lim_(ntooo)[(1)/(n^(2))sec^(2)""(1)/(n^(2))+(2)/(n^(2))sec^(2)""(4)/(n^(2))+.......+(1)/(n)sec^(2)1] a. 'tan1 b. 1/2tan1 c. 1/2sec1 d. 1/2cosec 1

Prove that tan20^(@)+tan70^(@)=(sec^(2)20^(@))/(sqrt(sec^(2)20^(@)-1))

Prove that: (1+sec 2theta)(1+sec2^(2)theta)(1+sec2^(3)theta)...... xx )(1+sec2^(n)theta) = tan2^(n)theta* cot theta

f(x)=tan(x/2)sec x+tan(x/2^(2))sec(x/2)+tan(x/2^(3))sec(x/2^(2))+.....+tan(x/2^(n))*sec(x/2^(n-1)) and g(x)=f(x)+tan((x)/(2^(n))) where x in(-(pi)/(2),(pi)/(2)) and n in N then g(x) is