I can't seem to calculate the min of this problem.

c=350,000-140x+0.030xsq

Could you please walk me through the problem?

thanks

Results 1 to 4 of 4

- Sep 26th 2008, 01:15 PM #1

- Joined
- Sep 2008
- Posts
- 2

- Sep 26th 2008, 01:23 PM #2

- Sep 26th 2008, 01:28 PM #3

- Joined
- Sep 2008
- Posts
- 2

- Sep 26th 2008, 01:43 PM #4

- Joined
- Jan 2008
- From
- Big Stone Gap, Virginia
- Posts
- 2,550
- Thanks
- 15
- Awards
- 1

$\displaystyle c=ax^2+bx+c$

$\displaystyle c=.030x^2-140x+350000$

$\displaystyle a=.030$

$\displaystyle b=-140$

$\displaystyle c=350000$

Substituting,

$\displaystyle x=\frac{-b}{2a}=\frac{140}{.06}=\frac{7000}{3}$

$\displaystyle c\left(\frac{7000}{3}\right)=.030\left(\frac{7000} {3}\right)^2-140\left(\frac{7000}{3}\right)+350000$

$\displaystyle c\left(\frac{7000}{3}\right)=\boxed{\frac{560000}{ 3}}$

That should be your minimum.