UPSEE Solved Model Paper 6

Since ‘C’ is an acute angle we can say that A and B will also be acute because both will be simultaneously positive and hence the triangle is acute. Acute angles lie in first quadrant, where there tangent is always positive.
∴ tan A . tan B = Positive . Positive = Positive
∴ tan A . tan B > 0
⇒ tan A . tan B > 1