Question

Evaluate:

3 sin 3B + 2cos ( 2B + 5°) ÷ 2 cos 3B - sin (2B - 10°)

when B =20°
PLEASE ANSWER......​

Answer 1

Step-by-step explanation:

3sin3×20° + 2cos (2×20° + 5°)

= --------------------------------------------------------

2cos 3×20° - sin (2×20° - 10°)

3sin60° + 2cos(40°+5°)

= -------------------------------------------

2cos60° - sin(40° - 10°)

3×√3/2 + 2cos 45°

= ---------------------------------------

2×1/2 - sin 30°

3√3/2 + 2× 1/√2

= ----------------------------------

1 - 1/2

3√3 / 2 + √2

= ----------------------------

2-1

------

2

3√3 +2√2

-----------------

2

= -----------------------------------

1/2

= 3√3 + 2√2

= 3×1.732 + 2×1.414

= 5.196 + 2.828

= 8.024 ans.