6.7 2変数関数の極値

1.

(a) $\displaystyle{1 + 2(x-1) + y-1 + (x-1)^{2} + 2(x-1)(y-1)}$

=2.6zw =1(b) $\displaystyle{-\frac{\pi}{2}(x-1) - (y - \frac{\pi}{2}) + \frac{1}{2}\left(-\fr...
...^{2}}{4}(x-1)^{2} - 2(x-1)(y - \frac{\pi}{2}) - (y - \frac{\pi}{2})^{2}\right)}$

(c) $\displaystyle{-(x-1) + y-1 + \frac{1}{2}\left(-(x-1)^{2} + 2(x-1)(y-1) - (y-1)^{2}\right)}$

(d) $\displaystyle{x + \frac{1}{2}(4x^{2} + 2xy)}$

2.

(a) $\displaystyle{f(1,0) = 1}$ 極大値 (b) $\displaystyle{f(0,4) = -32}$ 極小値, $f(0,0) = 0$ 鞍点 

(c) $\displaystyle{f(1,0) = -2}$ 極小値, $f(-1,0) = 4$ 鞍点 (d) $\displaystyle{f(1,1) = -3}$ 極小値