Question

tan25°•tan15°+tan15°•tan50+tan25°•tan50°

Answer 1

Answer:

1

Step-by-step explanation:

tan(15)tan(25)+tan(25)tan(50)+tan(15)tan(50)

=tan(15){tan(25)+tan(50)} +tan(25)tan(50)

now tan(25)+tan(50)=tan(75){1-tan(25)tan(50)} using tan(A+B)

= tan(15)tan(75){1-tan(25)tan(50)} + tan(25)tan(50)

now tan(15) and tan(75) are complimentary angles and hence they will cancel out.

so we are left with

1-tan(25)tan(50)+tan(25)tan(50)

=1