I think it's 56y + 7, is what I'm pretty sure of.
Turning points are inflection points
think
1st degree (linear) has no turning/inflecion points
2nd degree (quadratic, parabola) has 1 turning/inflection point
so
nth degree has n-1 turning/inflection point
this is 11th degree since highest power is 12
12-1=11
11 turning oints
X(30;0)
y(0;50)
substitue 0 for y and solve for x
substitute 0 in for x and solve for y
Answer:
Average speed is 3 kilometers an hour
Equation of a tangent line of a curve is:
y- y0 = f´ (x0) (x - x0 ). In this case: x0=1, y0=1
f´(x)=

(Derivation)
f´(x0)=

y - 1 = 1/2 ( x - 1 )
y - 1 = 1/2 x - 1/2
y = 1/2 x - 1/2 + 1
y =