If `x+1/x =7` then `x^2+1/x^2` is equal to

If cos theta =1/2 (x+1/x ) , then 1/2(x^(2) +1/(x^(2))) is equal to :

If f(x)=(x-1)/(x+1) then f(2x) is equal to

If f(x)=(x-1)/(x+1) then f(2x) is equal to

lim_(xrarr0) ((3x^2 + 2)/ (7x^2 +2))^(1/x^2) is equal to

If f(x) = (x-1)/(x+1) , then f(2) is equal to

If x_1=2tan^(-1)((1+x)/(1-x)),x_2=sin^(-1)((1-x^2)/(1+x^2)) , where x in (0,1), then x_1+x_2 is equal to (a) 0 (b) 2pi (c) pi (d) none of these

If x_(1) = 2 tan^(-1) ((1 + x)/(1 -x)), x_(2) = sin^(-1) ((1 - x^(2))/(1 + x^(2))), " where " x in (0, 1) , then 2( x_(1) + x_(2) ) is equal to

If f(x) = log_(e) ((1-x)/(1+x)) , then f((2x)/(1 + x^(2))) is equal to :

int( dx )/( x ( x^(7) +1)) is equal to

int (x^2 -1 )/ (x^3 sqrt(2x^4 - 2x^2 +1))dx is equal to