Transcript Think Break #5 Answer

Think Break #5
• Give the 1st and 2nd derivatives fx(x,y), fy(x,y),,
fxx(x,y), fyy(x,y), fxy(x,y) of each function:
• f(x,y) = 7 + 5x + 2y – 5x2 – 4y2 – 11xy
• f(x,y) = – 5 – 2x + y – x2 – 3y2 + 2xy
Think Break #5:Answer
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f(x,y) = 7 + 5x + 2y – 5x2 – 4y2 – 11xy
fx(x,y) = 5 – 10x – 11y
fy(x,y) = 2 – 8y – 11x
fxx(x,y) = – 10, fyy(x,y) = – 8, fyy(x,y) = – 11
f(x,y) = – 5 – 2x + y – x2 – 3y2 + 2xy
fx(x,y) = – 2 – 2x + 2y
fy(x,y) = 1 – 6y + 2x
fxx(x,y) = – 2, fyy(x,y) = – 6, fyy(x,y) = 2