If `x=7+4sqrt(3)\ \ a n d\ x y=1` , then `1/(x^2)+1/(y^2)=` 64 (b) 134 (c) 194 (d) `1/(49)`

If x=7+4sqrt(3)\ \ a n d\ x y=1 , then 1/(x^2)+1/(y^2)= ? (a) 64 (b) 134 (c) 194 (d) 1/(49)

If x=7+4sqrt(3) and xy=1, then (1)/(x^(2))+(1)/(y^(2))=64(b)134(c)194(d)(1)/(49)

If x+1/x=4, then x^4+1/(x^4)=? (a)196 (b) 194 (c) 192 (d) 190

If sqrt(y)=4x, then (x^(2))/(y) is (a) 2 (b) (1)/(16) (c) (1)/(4) (d) 4

If x+(1)/(x)=4, then x^(4)+(1)/(x^(4))=196(b)194 (c) 192(d)190

If x=3tant and y=3sect then find (d^2y)/(dx^2) at x=(pi)/(4) (a) 3 (b) (1)/(6sqrt2) (c) 1 (d) (1)/(6)

If x=3tan t and y=3sec t then find (d^(2)y)/(dx^(2)) at x=(pi)/(4)( a) 3( b) (1)/(6sqrt(2))(c)1(d)(1)/(6)

For the curve sqrt(x)+sqrt(y)=1 , (dy)/(dx) at (1//4,\ 1//4) is 1//2 (b) 1 (c) -1 (d) 2

For the curve sqrt(x)+sqrt(y)=1 , (dy)/(dx) at (1//4,\ 1//4) is (a) 1//2 (b) 1 (c) -1 (d) 2

If two different tangents of y^2=4x are the normals to x^2=4b y , then (a) |b|>1/(2sqrt(2)) (b) |b| 1/(sqrt(2)) (d) |b|<1/(sqrt(2))