Question

find the value of tan 21° tan 30° tan 69°

Answer 1

tan 21° = tan (90-69°)

tan 30° = tan (90-60°)

tan 69° = tan (90-21°)

So,

tan(90-69) tan(90-60) tan(90-21)

Which is,

cot69° cot60° cot21°

Answer 2

here is your answer ⬇⬇⬇⬇⬇⬇

tan 21°tan30° tan69°

= tan 21° tan 30° tan (90° - 21°)

= tan 21° × 1/√3 × cot 21°

= tan 21° × 1 / tan 21° × 1/√3

= 1/√3

hope it helps