If sin(α+β)=1 and sin(α-β)=12, then tan(α+2β)tan(2α+β) is equal to
(1)
Since, sin(α+β)=1
∴ α+β=π2 ⋯(i)
and sin(α-β)=12
⇒ α-β=π6 ⋯(ii)
On solving Eqs. (i) and (ii), we get
α=π3 and β=π6
Now, tan(α+2β)tan(2α+β)
=tan(2π3)tan(5π6)
=tan(π-π3)tan(π-π6)
=(-cotπ3)(-cotπ6)
=13×3=1