Let O(3,2) be the centre of the circle C2.
The tangent to the circle C1:x2+y2−2=0 at M(−1,1) is x−y+2=0
Now the perpendicular distance from O to the tangent is OP=∣23−2+2∣=23

Also AP=OA2−OP2=5−29
=21
Now tanθ=APOP=3
\therefore \mathrm{sin}\theta =\frac{3}{\sqrt{10}}=\frac{AP}{AN}&\mathrm{cos}\theta =\frac{1}{\sqrt{10}}
⇒AN=310AP=310×21=35=BN
Area of ΔANB=21⋅(AN2)sin2θ=21×910×53=61