SOLUTION: The minimum cost of maintaining an overhead crane depends on the number of hours the crane is in operation. The cost is given by the relation C=6t^2 - 36t +154, where C represents

Algebra.Com
Question 1209023: The minimum cost of maintaining an overhead crane depends on the number of hours the crane is in operation. The cost is given by the relation C=6t^2 - 36t +154, where C represents the cost in hundreds of dollars and t represents the time in hours that the crane has been operated. a) What is the minimum cost of maintaining the crane? (b) Find the number of hours the crane operates for this minimum maintenance cost.
Answer by math_tutor2020(3816)   (Show Source): You can put this solution on YOUR website!

I'll use x in place of t and use y in place of C.
The equation is y = 6x^2 - 36x + 154.
Compare this to the standard quadratic template y = ax^2+bx+c
a = 6, b = -36, c = 154

a = 6 is positive, so we have a parabola opening upward to indicate the vertex is the lowest point.
The vertex is located at (h,k)
h = -b/(2a)
h = -(-36)/(2*6)
h = 3
This is the x coordinate of the vertex.
It's the number of hours needed to reach the lowest cost.

Plug this x value back into the original equation to find its paired y value.
y = 6x^2 - 36x + 154
y = 6*3^2 - 36*3 + 154
y = 100
Therefore the vertex is located at (3,100).

Note that when completing the square, y = 6x^2 - 36x + 154 turns into the vertex form y = 6(x-3)^2 + 100.

y represents the cost in hundreds of dollars.
Whatever the y value is, multiply by 100.
Something like y = 2 represents 2*100 = 200 dollars
y = 100 represents 100*100 = 10,000 dollars.


Answers:
a. $10,000
b. 3 hours

RELATED QUESTIONS

The minimum cost of maintaining an overhead crane depends on the number of hours the... (answered by ikleyn)
The cost to rent a construction crane is $750 per day plus $250 per hour of use. What is (answered by JBarnum)
Crane A can unload the container ship in 10 hours, and crane B can unload it in 14 hours. (answered by MathLover1)
Crane A can unload the dumpster in 10 hours, and Crane B CAN UNLOAD it in 14 hours. Crane (answered by ptaylor)
I am building a scale model of a crane. The model is 2ft long, the actually crane is... (answered by Alan3354,MathLover1)
Tim Martinez is involved in a large construction project in the city. He needs to rend a... (answered by josgarithmetic)
In need of some major help! Please! the direct material cost of manufacturing a product... (answered by addingup)
The crane shown below is 10 feet high and has a boom of length 127 feet. The boom can... (answered by cleomenius)
An overhead crane is suspended from a ceiling by two chains. One chain is 4.6 m long and... (answered by ikleyn)