I don’t understand graphs at all help

I believe that the answer is the last option, f(x)=-x+2
It’s negative x because the graph is decreasing as the numbers positively increase. It’s positive 2 because (0,2) is your vertical intercept.
I hope this is helpful!

I) Apparently, we are to assume that AX and BX are tangent to the circle. Then OX bisects angle AOB and by the definition of trig functions,
  AX = AO*tan(π/6)
  AX = (12 cm)*(√3)/3
  AX = 4√3 cm

ii) The area of triangle AXO is
  triangle area = (1/2)(12 cm)(4√3 cm) = 24√3 cm²
The area of quadrilateral AXBO is twice that, 48√3 cm².

The area of sector ABO is
  sector area = (1/2)r²θ
  sector area = (1/2)(12 cm)²(π/3)
  sector area = 24π cm²

Then the shaded area is the difference between the area of the quadrilateral and the sector.
  shaded area = (48√3 -24π) cm²