#### Rengoku0510

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- Thread starter Rengoku0510
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The question does not concern the line, focus on the parabolic part.

You have a relationship given between x and y (containing the parameter: a).

Look for a pair of (x,y) coordinates that could help you determine the value of a.

If nothing else, experiment with the equation and numbers. I think you can do it!

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You have the equation. You are asked to find y at x=5. What do you get?

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I got 5. Still can't get to 3300...

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R(x)=ax(6-x). Plug in x=5. What's the result?I got 5. Still can't get to 3300...

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5=5(6-5) and answer is 1?R(x)=ax(6-x). Plug in x=5. What's the result?

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Can you name a point (other than (6, 0)) that lies on the parabola? Read it off the graph.

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Use whole numbers.

Can you name a point (other than (6, 0)) that lies on the parabola? Read it off the graph.

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Is it (3,6) and a=2?Use whole numbers.

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Please post your solution (how you found that a=2).Is it (3,6) and a=2?

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a is angle isn't it? So formula for angle is a=y/x so 6/3=2Please post your solution (how you found that a=2).

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No, it's not an angle. Nowhere in the problem an angle is mentioned. a is an unknown constant that you need to find in order to calculate y at x=5.a is angle isn't it? So formula for angle is a=y/x so 6/3=2

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I have no clue how to find a and I can't read it off the graphNo, it's not an angle. Nowhere in the problem an angle is mentioned. a is an unknown constant that you need to find in order to calculate y at x=5.

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R(x)=ax(6-x)I have no clue how to find a and I can't read it off the graph

Given that you know exactly what the values of x and R(x) are at the point (3,6), what do you get when you plug in those values in the above? And can you then find a?

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Sub in x=3 and y=6 into y=ax(6-x) and solve for a.

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I got a=2/3. I still can't get to the answer I feel hopelessSub in x=3 and y=6 into y=ax(6-x) and solve for a.

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Sub a=2/3 and x=5 into y=ax(6-x). y=3.3 which is $3300.

Can't believe I was struggling with such an easy question...

Thank you for your help everyone

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Good on you for not giving up!!

Sub a=2/3 and x=5 into y=ax(6-x). y=3.3 which is $3300.

Can't believe I was struggling with such an easy question...

Thank you for your help everyone

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All humans struggle, until they've gained sufficient experience to encode and recognize patterns -- thus remembering what to do.Can't believe I was struggling with such an easy question

Here's a basic fact from algebra, to keep in mind regarding equations containing unknowns (symbols representing variables and/or parameters).

If you have only one equation, then it can be solved for only one of the symbols in terms of all the others.

In other words, if you desire to solve one equation to find some numerical result (like: "what sales level"), then you'll first need to obtain (and substitute) numerical values for all of the symbols but one.

And, anytime you're given a graph with an equation, look for points where the (x,y) values are evident. Both the graph and the equation define the same relationship between y and x, so graphs are a great resource for experimenting with equations because they provide values to substitute.

With practice, this all becomes automatic. Then, we struggle with the next concepts until they become encoded. Our math toolbox (brain) grows.