функция 1) f(x) = 2х^2. 2) f(x) = 2x^2 + 3х

1. f(x) = 2 * х^2;

f(-2) = 2 * (-2)^2 = 2 * 4 = 8;

f(1/3) = 2 * (1/3)^2 = 2 * 1/9 = 2/9;

f(1) = 2 * 1^2 = 2 * 1 = 2;

2. f(x) = 2 * x^2 + 3 * х  -  4;

 f(-2) = 2 * (-2)^2 + 3 * (-2) -  4 = 8 - 6 - 4 = -2;

 f(1/3) = 2 * (1/3)^2 + 3 * 1/3  -  4 = 2 * 1/9 + 1 - 4 = 2/9 -3 = (2 - 27)/9 = -25/9 = -2*7/9;

 f(1) = 2 * 1^2 + 3 *1  -  4 = 2 + 3 - 4 = 1;

3. f(x) = х^2 - 9/x + 3;

 f(-2) = (-2)^2 - 9/(-2) + 3 = 4 + 4,5 + 3 = 11,5;

f(1/3) = (1/3)^2 - 9/(1/3) + 3 = 1/9 - 27 + 3 = 1/9 - 24 = -215/24 = -8 * 23/24;

f(1) = 1^2 - 9/1 + 3 = 1 - 9 + 3 = -5.