Question

1-tan20×tan25=tan20+tan25​

Answer 1

Solution :- As we know that ,

Tan( A + B ) = tanA + TanB / 1 - TanA*TanB

similarly,

Tan45° = Tan ( 20° + 25°) = Tan20° + tan25°/1- Tan20°Tan25°

1 = tan20° + tan25° / 1 - tan20° tan25°

1 - tan20° tan25° = tan20° tan25° Answer ✔