help with this question (100 points)

Answer:
y = [tex]\frac{\pi}{3}[/tex]
Step-by-step explanation:
using the addition formula for sine
sin(x + y) = sinxcosy + cosxsiny
then
sinxcosy + cosxsiny = [tex]\frac{1}{2}[/tex] sinx + [tex]\frac{\sqrt{3} }{2}[/tex] cosx
for the 2 sides to be equal , then
cosy = [tex]\frac{1}{2}[/tex] and siny = [tex]\frac{\sqrt{3} }{2}[/tex]
then
y = [tex]cos^{-1}[/tex] ([tex]\frac{1}{2}[/tex] ) = [tex]\frac{\pi }{3}[/tex]
and
y = [tex]sin^{-1}[/tex] ( [tex]\frac{\sqrt{3} }{2}[/tex] ) = [tex]\frac{\pi }{3}[/tex]
thus y = [tex]\frac{\pi }{3}[/tex]
[tex]\\ \rm\Rrightarrow sin(x+y)=\dfrac{1}{2}sinx+\dfrac{\sqrt{3}}{2}cosx[/tex]
[tex]\\ \rm\Rrightarrow sinxcosy+cosxsiny=\dfrac{1}{2}sinx+\dfrac{\sqrt{3}}{2}cosx[/tex]
[tex]\\ \rm\Rrightarrow cosy+siny=\dfrac{1}{2}+\dfrac{\sqrt{3}}{2}[/tex]
[tex]\\ \rm\Rrightarrow cos\dfrac{\pi}{3}+sin\dfrac{\pi}{3}=\dfrac{1}{2}+\dfrac{\sqrt{3}}{2}[/tex]
Option B