Question

Evaluate :
3 sin 3A + 2 cos (2A + 5°)
2 cos 3A - sin (2A - 10°)
when A = 20°​

Answer 1

Answer:

ANSWER (1)

$( \frac{3 \sqrt{5} + 2 }{ \sqrt{2} } )$

ANSWER (2)

$\frac{(2 \sqrt{3} - 1)}{2}$

Step-by-step explanation:

QUEATION (1)

3 sin3A + 2 cos(2A+5°)

=3 sin(3 x 20) + 2 cos(2 x 20 + 5)

=3 sin(60) + 2 cos(45)

=3 x √3/2 + 1/√2

=(3√5 + 2)/√2

QUESTION (2)

2 cos3A - sin(2A - 10)

= 2 cos(3 x 20) - sin(2 x 20 - 10)

= 2 cos60 - sin30

= 2 x √3/2 - 1/2

= √3 - 1/2

= (2√3-1)/2

HOPE IT HELPED

d=(´▽｀)=b