# Math Help - Linear Approximation problem

1. ## Linear Approximation problem

The revenue from the sales of a rare, limited-production luxury car are forecast by R(x) = 3,000,000(1-3/x) when x greater than or equal to 4. Use differentials to estimate the increase in revenue from the sale of one more car from a sales level of 5.

2. Originally Posted by McDiesel
The revenue from the sales of a rare, limited-production luxury car are forecast by R(x) = 3,000,000(1-3/x) when x greater than or equal to 4. Use differentials to estimate the increase in revenue from the sale of one more car from a sales level of 5.
$\Delta R \approx \frac{dR}{dx} \Delta x$

$\Delta R \approx \frac{9000000}{x^2} \Delta x$

Now put $\Delta x=1$ and $x=5$

CB