Answer:

Step-by-step explanation:
The equation of the curve is

To find the equation of tangent we need to differentiate this equation w.r.t x
So, differentiating we get

This would give the slope of the tangent line at any given point of which x coordinate is known. In the present case it is 
Then slope would accordingly be

= ∞
For,
, 
Equation of tangent line, in the point slope form, would be 
a) 1,000 + 0 + 40 + 9
b) 40,000 + 3,000 + 800 + 70 + 0
c) 8,000,000 + 100,000 + 5
24 since .25 times 4 = 1 so try 6 times 4 and it equals 24
Total to pay per autograph= 8.00+13.25=21.25
Number of autographs you can buy = 2(21.25)= 42.5
You can buy two autographs and have a change of 8.25