Question

evaluate 3 cos 55/7 sin 35-3root ( tan10 tan 30 tan40 tan50 tan80)​

Answer 1

Answer:

GIVEN

3cos55 / 7sin35 - 4/7(cos 70 cosec 20 ) / (tan5 tan25 tan45 tan65 tan85 )

USE

tan x = cot (90-x)

cot x = tan (90-x)

sin x = cos (90-x)

cos x = sin (90-x)

= [3 (cos55 / 7cos55)] - 4[(cos70 / sin20)] / 7 [tan5 tan25 tan45 tan65 tan85]

= (3 / 7) - 4 / 7(tan5 cot5 tan25 cot25 tan45)

= 3/7 - 4/7

= - 1 / 7

Answer 2

Answer:

-4/7

Step-by-step explanation:

3cos55/7sin35=3/7

√3(tan 10. tan80. tan 40. tan50.1/√3)=√3×1×1×1/√3

=√3/√3=1

3/7-1=-4/7