volume

$1^3$

$25.[-/2$ Points$]$

BERRAPCALCBR$73\mathrm{.}4\mathrm{.}003.$

An airline finds that if it prices a cross$-$country ticket at $$400,$ it will sell $300$ tickets per day. It estimates that each $$10$ price reduction will result in $50$ m $($and the number of tickets sold$)$ that will maximize the airline's revenue.

ticket price

number of tickets

$26.[-/2$ Points$]$

BERRAPCALCBR$74\mathrm{.}3\mathrm{.}004.$

Find the derivative of the function.

$f(x)=ln(x^4+7)$