Question

sin(40)-cos(70)=root3cos(80)

Answer 1

Answer:

Hey mate,

Step-by-step explanation:

→ L.H.S. :- sin 40 - cos 70              using sin C - sin D 2cos C + D /2 sin C-D/ 2

→  sin 40 - cos ( 90 - 20)

→  sin40−sin20  

→  2cos30.sin10.           sin(90−80)=cos80

→ 2 √3 /2 X cos 80

→ √ 3 cos 80 °  R .H. S

hope it was helpful