Five sisters - alexandra, emily, lisa, martha, and laura decide to purchase a big screen tv as a birthday gift for their mother. - martha agrees to pay 20% of the cost -emily gives $75 -alexandra pays 25% of the cost -laura gives $75 - lisa contributes one-half of the cost. what is the total cost of the big screen tv? what amount will each sister pay?

First locate the turning point (vertex) of the graph. which is at the coordinates x=5 and y=9 or (5; 9).to determine whether it's a maximum or mininum value, you have to discern whether the vertex's y-value is the highest value or lowest value the graph can reach. since the vertex's y-value, 9 is the highest value the graph can reach, it will be a maximum.another basic way to determine whether the vertex's value is max or min is to see if the graph is smiling or sad. if it's smiling, the turning point/vertex would be a minimum, while a sad parabola would have a maximum y-value at the vertex.