Factor out the cos<span>θ:
</span>cosθ (2sin<span>θ + sqrt3) = 0
</span>Therefore, the only ways this can happen are if either cosθ = 0 or if (2sin<span>θ + sqrt3) = 0
</span>The first case, cosθ = 0 only at θ <span>= pi/2, 3pi/2.
</span>The second case, <span>(2sin<span>θ + sqrt3) = 0 simplifies to:
</span></span>sin<span>θ = (-sqrt3)/2
</span><span><span>θ = 4pi/3, 5pi/3
</span></span><span><span>Therefore the answer is A.
</span></span>
missing letter is 2
missing letter is 3
missing letter is 1
Hope it is helpful to you ☺️
1. By the Law of Sines, you have:
SinA/a=SinB/b=SinC/c
2. You don't need the fraction SinC/c, so you can eliminate it. Then:
SinA/a=SinB/b
A=40°
a=19
B=m∠b
b=13
3. When you substitute this values into SinA/a=SinB/b, you obtain:
SinA/a=SinB/b
Sin(40°)/19=SinB/13
SinB=13xSin(40°)/19
m∠b=SinB^-1(13xSin(40°)/19)
m∠b=26.1°
Therefore, the answer is: 26.1 degrees.