Write three functions. In the first function, y should vary directly with x. In the second function, y should vary inversely wit
h x. In the function, the relationship between x and y should be neither inverse variation nor direct variation. Describe the graph of each function and give a real world example for each.
<span>1)y varies directly with x , k= 5/3 x=9, y=5/3x=5/3(9)=15
example: i want to buy some candy canes and the cost per pound is $9.00 how much will it cost to buy 3 pounds? how much would a half pound cost.
description: since k is constant we can find k by dividing y coordinate by the x coordinate, y1/x1=k y2/x2=k.
2) y varies inversely with x, k=5/2, x=10, xy=5/2 - 10y=5/2 - y=5/2*1/10=1/2*1/2=1/4
example: if i get paid $10 dollars an hour, how much will i make in 12 hours?
description: since k is constant, i can find k given any point by multiplying x coordinate by the y coordinate, x1y1=k - x2y2=k , the lines never cross the axes
3) y=2x-3
description': the graph crosses through the points -3 an 1.5 and it's a single line.
So for this you need the two solutions to be x= -9 and x=3 then move over the numbers and put in brackets (x+9)(x-3) then multiply together x^2+9x-3x-27 then combine like terms to get x^2+6-27
