Question

tan80°-tan10°/ tan 70°=k then k=​

Answer 1

Step-by-step explanation:

= {(sin80°/cos80°)-(sin10°/cos10°)} / (sin70°/cos70°)

= {(sin80° cos10°-cos80° sin10°)/cos80°cos10°} / [sin70°/cos70°]

sin(80°-10°) * cos70°

=. ..................................................

cos80° *cos10° * sin70°

sin70° cos70°

= .............................................

cos80° *cos10° * sin70°

cos70°

= ......................................

cos80° cos10°

cos(80°-10°)

= .......................................

cos80° cos10°

. cos80° cos10°+ sin80°sin10°

= ...................................................................

cos80° cos10°

= 1+ tan80°tan10°

= 1+ tan(90°-10°) tan10°

= 1+ cot10°tan10°

= 1+1

=2

then k=2