Maximum are between two functions

[nubshat]

Question:

My solution:



I just want to know if I have the right solution (k=4.5 A=9/13) because many people in my class say they got a different answer but I think mine is right.
Can someone please just confirm my answer or tell me what I did wrong?

 

[stapel]

I can't read the text in the graphic; sorry. Please type it out. Thank you! ;-)

 

[srmichael]

I got the same answer as you. What were the others getting for their answer?

 

[nubshat]

Others were getting 4.9, a lot of them too.. glad to know I'm right though, thanks a lot