Question

tan 1 tan 10 tan 20 tan 70 tan 80 tan 89 = 1

Answer 1

tan(90-1)×tan(90-10)×tan(90-20)×tan70 x tan80× tan89 =1

cot89×cot80×cot70×tan70×tan80×tan89

we know that cot@=1/tan@
so,
1/tan89×1/tan80×1/tan70×tan89×tan80×tan70=1

HENCE PROVED.
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Answer 2

Hey there !!

Answer: 1 .

Step-by-step explanation:

= tan 1 . tan 10 . tan 20 . tan 70 . tan 80 . tan 89  

= tan 1 . tan 10 . tan 20 . tan( 90 - 20 ) ... tan (90 - 10 ) . tan ( 90 - 1) 

= tan 1 . tan 10  . tan 20 . cot 20 . cot 10 . cot 1 

= tan 1 . cot 1 . tan 10 . cot 10 . tan 20 . cot 20 .

= 1 x 1 x 1.

= 1 .

Hence, it is solved .

THANKS

#BeBrainly .