The value of tan1°.tan2°tan3°..... tan89° is equal to

The value of tan1°.tan2°tan3°..... tan89° is equal to

 A) -1

 B) 1

 C) pi/2

 D) 2

 Correct  Option is

 B) 1

tanθ=cot(90∘−θ)

∴tan1∘=cot89∘

cot89∘=tan89∘1​

Similarly all the term will cancel out each other, except tan45∘, whose value is equal to 1