- 7 1/2:(-5)= - 15/2:(-5)= - 15/2*(-1/5)=3/2= 1 1/2
Весь путь- 100 %
1) 100 - 65 = 35 (%) осталось пройти;
2) 7,7 : 35 = 0,22 (км) в 1 %;
3) 0,22 * 100 = 22 (км) весь путь.
Ответ: весь путь - 22 км
![f(x,y,z)=\sqrt zx^y\\\frac{\partial f}{\partial x}=yx^{y-1}\sqrt z\\\frac{\partial f}{\partial y}=x^y\ln x\sqrt z\\\frac{\partial f}{\partial z}=\frac{x^y}{2\sqrt z}](https://tex.z-dn.net/?f=f%28x%2Cy%2Cz%29%3D%5Csqrt+zx%5Ey%5C%5C%5Cfrac%7B%5Cpartial+f%7D%7B%5Cpartial+x%7D%3Dyx%5E%7By-1%7D%5Csqrt+z%5C%5C%5Cfrac%7B%5Cpartial+f%7D%7B%5Cpartial+y%7D%3Dx%5Ey%5Cln+x%5Csqrt+z%5C%5C%5Cfrac%7B%5Cpartial+f%7D%7B%5Cpartial+z%7D%3D%5Cfrac%7Bx%5Ey%7D%7B2%5Csqrt+z%7D)
Правильный только один - производная по z.
![u=xy^2+z^2+5x\\\frac{\partial u}{\partial x}=y^2+5\\\frac{\partial u}{\partial y}=2xy\\\frac{\partial u}{\partial z}=2z\\grad(u)_M=(y^2+5)\bar i+2xy\bar j+2z\bar k=(0+5)\bar i+2\cdot(-1)\cdot0\bar j+2\cdot1\bar k=\\=5\bar i+2\bar k](https://tex.z-dn.net/?f=u%3Dxy%5E2%2Bz%5E2%2B5x%5C%5C%5Cfrac%7B%5Cpartial+u%7D%7B%5Cpartial+x%7D%3Dy%5E2%2B5%5C%5C%5Cfrac%7B%5Cpartial+u%7D%7B%5Cpartial+y%7D%3D2xy%5C%5C%5Cfrac%7B%5Cpartial+u%7D%7B%5Cpartial+z%7D%3D2z%5C%5Cgrad%28u%29_M%3D%28y%5E2%2B5%29%5Cbar+i%2B2xy%5Cbar+j%2B2z%5Cbar+k%3D%280%2B5%29%5Cbar+i%2B2%5Ccdot%28-1%29%5Ccdot0%5Cbar+j%2B2%5Ccdot1%5Cbar+k%3D%5C%5C%3D5%5Cbar+i%2B2%5Cbar+k)
Р=4 см
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