<u>Answer-</u>
At
the curve has maximum curvature.
<u>Solution-</u>
The formula for curvature =

Here,

Then,

Putting the values,

Now, in order to get the max curvature value, we have to calculate the first derivative of this function and then to get where its value is max, we have to equate it to 0.

Now, equating this to 0






Solving this eq,
we get 
∴ At
the curvature is maximum.
If you paid $22.26 after the discount and tax then 30% is 0.30 and 30% OFF is 1-0.30=0.70
Tax is 6% or 0.06 and along with the initial is 1+0.06=1.06 so P is original price in P×0.70×1.06=22.26
P×0.742=22.26
P=$30 was the original price
$1.35 x 10 = $13.50 for 10 gallons
$23.50 - $13.50 = $10.00
$1.35 x 7 = $9.45 for 7 more gallons
17 gallons is $22.45
17/27 = 459 miles but I'm missing the last bit of change so round it up to 460 for a total of miles