Question

solve this question ​

Answer 1

Answer:

Step-by-step explanation:

By trigonometric

Triangle ADE, ADB, BDE

sin x / sin 10. sin 20 / sin ( 30 +x ) . sin 80 / sin 60

DA /DE. DE/ DB . DB/DA =1

simplify:

2 cos ² 10 sin x = sin 60 sin (30 +x)

= √3/4 cos x + 3/4 sin x

Now,

tan x= √3 /1+4 cos 20

= √3 sin 20 / sin 20 + sin 40 + sin 40

= √3 sin 20 / 2sin 30  cos 10 + sin 40

= √3 sin 20 / sin 80 + sin 40

= √3sin 20/ √3cos 20

= tan 20

tan x = tan 20

x = 20