The correct option is B 2
Given:
x2+2xsin(xy)+1=0
⇒(x+sin(xy))2+(1−sin2(xy))=0⇒(x+sin(xy))2+cos2(xy)=0
Which is possible only when both terms are individually equal to zero, so
⇒x+sin(xy)=0 and cos2(xy)=0⇒sin(xy)=−x and sin(xy)=±1
Case 1:sin(xy)=1⇒x=−1,
⇒−sin(y)=1⇒siny=−1⇒y=3π2
Case 2:sin(xy)=−1⇒x=1,
⇒sin(y)=−1⇒siny=−1⇒y=3π2
Hence, there are 2 ordered pairs (−1,3π2) and (1,3π2).