Plz help me with this math question

pemdas

Step-by-step explanation:

take 8x8x8 then divide by 2, then add 9

R = √2

α = π/4 or 45°

Step-by-step explanation:

R cos(2n + α)

Use angle sum formula:

R [cos(2n) cos α − sin(2n) sin α]

R cos(2n) cos α − R sin(2n) sin α

Match the coefficients:

R cos α = 1

R sin α = 1

Divide:

tan α = 1

α = π/4 or 45°

Solve for R:

R cos(π/4) = 1

R / √2 = 1

R = √2