## Help with a homework assignment: profit equation

Quadratic equations and inequalities, variation equations, function notation, systems of equations, etc.
gte
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Joined: Mon Nov 05, 2012 6:00 pm
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### Re: Help with a homework assignment: profit equation

6. Show a graph of the profit equation. Be sure to label the horizontal and vertical axes.
• Label the y-intercept with an ordered pair of numbers. Explain these values in the context of the problem.
• Label both x-intercepts with ordered pairs of numbers, approximating values to the nearest tenth. Explain these values in the context of the problem.
• Label the vertex with an ordered pair of numbers. Explain these values in the context of the problem.

6.)

I'm guessing X is items produced and Y is profit? So all numbers should be in the upper right quadrant of the graph where positive X and Y numbers reside?

profit of 0 = \$0
profit of 5 = \$1518
profit of 10 = \$2619
profit of 15 = \$3560
profit of 20 = \$4341
profit of 25 = \$4962
profit of 30 = \$5423
profit of 35 = \$5724
profit of 40 = \$5865
profit of 42 = \$5876.6
profit of 45 = \$5846
profit of 50 = \$5667
profit of 55 = \$5328
profit of 60 = \$4829
profit of 65 = \$4170
profit of 70 = \$3351
profit of 75 = \$2372
profit of 80 = \$1233
profit of 84 = \$206.6
profit of 84.7 = 16.45
profit of 84.8 = -10.97
profit of 85 = \$-66

I believe the Y intercept is 0 profit (0, 0)
I believe the first X intercept is 0 items (0, 0), with the second being 84.7 items (84.7, 0)
I believe the vertex is 42, 5876.6

maggiemagnet
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Joined: Mon Dec 08, 2008 12:32 am
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### Re: Help with a homework assignment: profit equation

If this is from the first equation you posted, then you can find the exact x-intercepts by plugging zero in for y and then plugging the result into the Quadratic Formula. There's also a formula for the vertex, if you'd like to be exact for that, too.