Question

Please help now.......​

Answer 1

Answer:

1

Step-by-step explanation:

sin(50+\theta)-cos(40-\theta)\\+tan1\degree tan10\degree tan20\degree tan70\degree tan80\degree tan89 \degree

=sin[90-(40-\theta)]-cos(40-\theta)\\+(tan1\degree tan89\degree) (tan10\degree tan80\degree) (tan20\degree tan70 \degree)

=cos(40-\theta)-cos(40-\theta)\\+[tan(90-89\degree)tan89] [tan(90-80\degree) tan80\degree] [tan(90-70\degree )tan70 \degree]

=0+(cot89tan89)(cot80tan80)(cot70tan70)

=1\times 1 \times 1