Question

prove that tan 15 degrees into Tan 20 degrees into tan70 degrees into tan 75 degrees equal to 1​

Answer 1

Explanation:

tan15.tan20.tan70.tan75

= tan15.tan20.cot(90-70).cot(90-75)  ............... tanx = cot(90-x)

= tan15.tan20.cot20.cot15

=tan15.tan20. 1/tan20.1/tan15   .............. tan 15 and tan15 gets cancelled

                                                       ............  tan20 and tan20 gets cancelled

=1

Answer 2

Answer:

Please see the attachment for step by step explanation

Explanation:

tan15°• tan20°• tan70°• tan75° = 1

LHS = tan15°• tan75°• tan20°• tan70°= 1

= cot(90-15) • tan75°• cot(90-20) • tan70° [bcoz tan theta = cot (90- theta]

= cot75°• tan75°• cot70°• tan70°

= 1•1

[bcoz tan theta • cot theta = 1]

= 1

therefore, LHS = RHS

HOPE IT HELPS ^_^

marks as BRAINLIEST... if possible

thx