f(x)=e^(-x/2)f(0)=e^(0/2)=e^0=1f'(x) = -1/2 * e^(-x/2)f'(0)= -1/2* e^0 = -1/2y = 1 - 1/2(x-0) = 1-1/2xответ: y = -0.5x + 1