Maximizing objective function

[9_7]

Hey guys I'm just wondering if you could explain q9 of graphs and relations in the vcaa 07 exam 1? I'm really having trouble doing these!

http://www.vcaa.vic.edu.au/Documents/exams/mathematics/2007furmath1.pdf

[Will T]

Haha my teacher made me do this exam class.
The answer is A (1) because the only time that the point (100,0) will be the maximum value is when k = 1. Try it out and you'll see what I mean Hope this helped.

[Stick]

What you need to do is set up four equations by substituting each co-ordinate into the objective function. Now trial each value of k until the equation with (100,0) is the largest of the four.

[9_7]

What if there are no values given?

[Stick]

That would be unlikely for this sort of question, but you'd need to rearrange the function and find a suitable gradient.