# Maximum value.

• Apr 12th 2009, 10:45 PM
usagi_killer
Maximum value.
• Apr 12th 2009, 11:22 PM
CaptainBlack
Quote:

Originally Posted by usagi_killer

Without knowing what functions $f,\ g, \ h$ are we cannot say what the actual maximum is but you can establish an upper bound, because clearly:

$a=3f+4g+10h\le100$

when $f,\ g,\ h$ satisfy the constraint $|f+g+h|\le10$

CB
• Apr 13th 2009, 12:57 AM
usagi_killer
Sorry!! wrong question lols,
sorry for the inconvenience!!!

The revised question is:

Find the maximum value of $a(x) = 3f(x) + 4g(x) + 10h(x)$ given that $f(x)^2 + g(x)^2 + h(x)^2 \leq 9.$

i've tried putting everything in terms of each other but its not working haha