Prove that: 2 Tan 70 = Tan 80 - Tan 10 - Maths - Trigonometric Functions

Question

Prove that:
2 Tan 70 = Tan 80 - Tan 10

Anuradha Sharma · Accepted Answer

Dear Student,

80 = 10 + 70

Taking tan both side,

tan 80 =tan10+tan701-tan10tan70

tan80 - tan10tan70tan80 = tan10 + tan70

tan80 - tan70 = tan10 + tan70 [ As tan10 tan80 = tan10 tan(90-10)=
tan10cot10=1]

tan80 = tan10 + 2tan70

Regards