Question

Prove that: tan 20. tan 30. tan 40. tan 80 = 1

Answer 1

tan 20=0.3640

tan 30=0.5774

tan 40=0.8391

tan 80=5.6713

0.3640*0.5774*0.8391*5.6713=1

0.2101736*4.75878783=1

1.00017156986728=1

the answer will be approx 1.