The Student Room Group
Uni students - Complete our survey >>
Uni students - Complete our survey >>
Uni students - Complete our survey >>

Help needed

How do I “write down the least value of x^2+8x+2”? I have already completed the square
Reply 1
Avatar for B_9710
B_9710
18
When you complete the square you get (x+4)^2-14 now you have to make this expression as small as possible so this Weill be when (x+4)^2 is 0. Can you see what the min value will be now?
Original post by B_9710
When you complete the square you get (x+4)^2-14 now you have to make this expression as small as possible so this Weill be when (x+4)^2 is 0. Can you see what the min value will be now?


-4
Original post by B_9710
When you complete the square you get (x+4)^2-14 now you have to make this expression as small as possible so this Weill be when (x+4)^2 is 0. Can you see what the min value will be now?


Wait -4 fits that but the answer is -14
Reply 4
Avatar for B_9710
B_9710
18
Original post by Reece.W.J
Wait -4 fits that but the answer is -14


The minimum value is achieved when x=-4 but we're finding the minimum value of the expression (x+4)^2-16 , which is what when x=-4?
Original post by B_9710
The minimum value is achieved when x=-4 but we're finding the minimum value of the expression (x+4)^2-16 , which is what when x=-4?


-16 but I thought -14 because 930C2B27-D8D9-451E-BEB1-34D87288D7B9.jpg.jpeg
Reply 6
Avatar for B_9710
B_9710
18
Original post by Reece.W.J
-16 but I thought -14 because 930C2B27-D8D9-451E-BEB1-34D87288D7B9.jpg.jpeg


No it's -14 you're right I just wrote it down wrong.
Original post by B_9710
No it's -14 you're right I just wrote it down wrong.


Ok ty. I’ve also done this one 2B32B56B-376A-4812-ACF6-4DEA08FD81BE.jpg.jpeg how do I find the maximum value for this one? F1767D9D-F663-4152-94E8-DAB8F6EC5939.jpg.jpeg

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you