Answer:
C. 4
Step-by-step explanation:
arc length = radius*θ ,
where θ is an angle in radians.
12 = 3*θ
θ = 12/3 = 4
refer to the picture for step by step answer
hope it helps
15.4
f(4) = 3×4^2+15
4^2=16
3×16
48+15
63
f(4)=63
