If `((a^2+1)^2)/(2a-i)=x+i y ,` then `x^2+y^2` is equal to a. `((a^2+1)^4)/(4a^2+1)` b. `((a+1)^2)/(4a^2+1)` c. `((a^2-1)^2)/((4a^2-1)^2)` d. none of these

If ((a^(2)+1)^(2))/(2a-i)=x=iy, then x^(2)+y^(2) is equal to ((a^(2)+1)^(4))/(4a^(2)+1) b.((a+1)^(2))/(4a^(2)+1) c.((a^(2)-1)^(2))/((4a^(2)-1)^(2)) d.none of these

int(x)/(4+x^(4))dx is equal to (1)/(4)tan^(-1)x^(2)(b)(1)/(4)tan^(-1)((x^(2))/(2))(c)(1)/(2)tan^(-1)((x^(2))/(2))(d) none of these

If (1-i)x+(1+i)y=1-3i , then (x,y) is equal to (a) (2,-1) (b) (-2,1) (c) (-2,-1) (d) (2,1)

If (1-i)x+(1+i)y=1-3i , then (x,y) is equal to (a) (2,-1) (b) (-2,1) (c) (-2,-1) (d) (2,1)

If (1-i)x+(1+i)y=1-3i , then (x,y) is equal to (a) (2,-1) (b) (-2,1) (c) (-2,-1) (d) (2,1)

If y=(1+1/(x^2))/(1-1/(x^2)) , then (dy)/(dx) = a. -(4x)/((x^2-1)^2) b. -(4x)/(x^2-1) c. (1-x^2)/(4x) d. (4x)/(x^2-1)

int(x^4-1)/(x^2sqrt(x^4+x^2+1))dx= sqrt(x^2+1/(x^2)+1)+C (sqrt(x^4+x^2+1))/(x^2)+C (sqrt(x^4+x^2+1))/x+C (d) none of these

If sin^(-1)x+sin^(-1)y=pi/2 , then (1+x^4+y^4)/(x^2-x^2y^2+y^2) is equal to a)1 b)2 c) 1//2 d)None of these

If the polar with respect to y^2 = 4ax touches the ellipse x^2/alpha^2 + y^2/beta^2=1 , the locus of its pole is (a) (x^2)/(alpha^2)-(y^2)/(4a^2 alpha^2"/"beta^2)=1 (b) (x^2)/(alpha^2)+(beta^2 y^2)/(4a^2)=1 (c) a^2x^2+b^2y^2=1 (d) None of these

None of these int(2x)/((1-x^(2))sqrt(x^(4)-1))dx is equal to :( A) sqrt((x^(2)-1)/(x^(2)+1))+c(B)sqrt((x^(2)+1)/(x^(2)-1))(C)sqrt(x^(4)+1)(D) None of these