For the sets of real numbers given by
$R_1=\{(x,y):x∈R, y∈R\,x^2+y^2≤25\}$
$R_2=\{(x,y):x∈R, y∈R\,9y≥4x^2\}$
$R_1∩R_2$ is
Answer & explanation
Correct answer: option 4
Here $x^2+y^2≤25$ are the elements of R1 lying with in and on the circle $x^2+y^2=25$, where as $4x^2≤9y$ are the elements of R2 lying with in and on the parabola $4x^2=9y$.
Hence relation $R_1∩R_2$ is not a function.
Hence (D) is the correct answer.