Simplify sin 4 theta/1+cos4 theta using half angle formula

How do i do this? i don’t understand

Nick has box brads. he uses 4 brads for the first project. nick let’s b represent the original number of brads and finds that for the second project, the number of brads he uses is 8 more than half the difference of b and 4. write an expression to represent the number of brads he uses for the second project.

X2 + y 2 = 36 x + y = 6 solve the system of equations.