Question

Tan 5° tan 13° tan77° tan85° = 1

Answer 1

Answer:

tan5 tan13 tan77 tan85

= tan(90-85) tan(90-77) tan77 tan85

= cot85 cot77 tan77 tan85

= (cot85 × tan85) (cot77 × tan77)

= (1)(1)

= 1

Formula used :

• tan(90-x) = cotx
• tanx × cotx = 1

Answer 2

Answer:

this is the answer of ur question