Thread: Two problems

Originally Posted by icemanfan

That's a start. When you multiply it out, you will find that the function is a parabola. Where does the parabola achieve its maximum value?

by changing to f(x) = a(x-h)²+k form ?

Originally Posted by myaa02

by changing to f(x) = a(x-h)²+k form ?

Yes, you want to change the equation to that form. Be careful, though. You made a mistake in multiplying it out. The correct equation is .

Originally Posted by icemanfan

Yes, you want to change the equation to that form. Be careful, though. You made a mistake in multiplying it out. The correct equation is .

how did you get 2000x if you multiply 100x with 80 ?

nvm i just got it lol

what do you do after ?

Originally Posted by myaa02

what do you do after ?

You should get .

Then, observe that the parabola achieves its maximum value at the vertex. What is the vertex of this parabola?

Originally Posted by icemanfan

You should get .

Then, observe that the parabola achieves its maximum value at the vertex. What is the vertex of this parabola?

vertex is -10

Originally Posted by myaa02

vertex is -10

Incorrect. Remember, the vertex is a point. Also, the x-value of the vertex is not -10.

Originally Posted by icemanfan

Incorrect. Remember, the vertex is a point. Also, the x-value of the vertex is not -10.

i seriously don't know how to get the vertex.

Originally Posted by myaa02

i seriously don't know how to get the vertex.

If the equation of the parabola is ,
then the vertex of the parabola is (h, k).

Originally Posted by icemanfan

If the equation of the parabola is ,
then the vertex of the parabola is (h, k).

so its (-10,490000)

Originally Posted by myaa02

so its (-10,490000)

The vertex is (10, 490000).

Originally Posted by icemanfan

The vertex is (10, 490000).

now how am I supposed to find the " new markup " in order to maximize the revenue ?

Originally Posted by myaa02

now how am I supposed to find the " new markup " in order to maximize the revenue ?

The function is maximized when x = 10. The markup is 100x, so what should the markup be?

Originally Posted by icemanfan

The function is maximized when x = 10. The markup is 100x, so what should the markup be?

So, the markup should be 1000 ?

Originally Posted by myaa02

So, the markup should be 1000 ?

Yes, that's correct.