06.09.2021 Views

College Algebra & Trigonometry, 2018a

College Algebra & Trigonometry, 2018a

College Algebra & Trigonometry, 2018a

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

244 CHAPTER 4. FUNCTIONS<br />

So, our final formula for the cost is:<br />

C =6x 2 +4xh<br />

but we already know that we want to spend $72 on the box, so we can say that:<br />

72 = 6x 2 +4xh<br />

This means that :<br />

72 − 6x 2<br />

4x<br />

or<br />

= h<br />

18<br />

x − 1.5x = h<br />

The reason why this is important is that it will allow us to express the volume of<br />

the box in terms of x. Remember that the volume was:<br />

V = x 2 h<br />

so now we can see that:<br />

( ) 18<br />

V = x 2 x − 1.5x<br />

or<br />

V =18x − 1.5x 3

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!