y = (1/2)*x² - x + 1.
1) y = (1/2)*0² - 0 + 1 = 1;
2) y = (1/2)*(-1)² - (-1) + 1 = 1/2 + 2 = 5/2;
3) y = (1/2)*(-2)² - (-2) + 1 = 2 + 2 + 1 = 5;
4) y = (1/2)*(4)² - 4 + 1 = 5.
Решение во вложения……………..
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<span>1+(1-sin^2a)/(1-cos^2a) = 1 - </span>(cos²x) / (sin²x) = 1 - ctg²x = (cos2a) / (sin²x)