Agardener determines the cost of planting daffodil bulbs to be $2.40 per square foot. how much will it cost to plant daffodil bulbs in a rectanglular garden that is 12 feet longand 5 feet wide? a)$40.80b)$60c)$144d)$81.60

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204