>> x1 = @(t) heaviside(t) - heaviside(t-1);
>> x2 = @(t) heaviside(t) - 2*heaviside(t-0.5) + heaviside(t-1);
>> x3 = @(t) heaviside(t) - 2*heaviside(t-0.25) + 2*heaviside(t-0.75) - heaviside(t-1);
>> x4 = @(t) heaviside(t) - 2*heaviside(t-0.25) + 2*heaviside(t-0.5) - 2*heaviside(t-0.75) + heaviside(t-1);
>> x5 = @(t) heaviside(t) - 2*heaviside(t-0.125) + 2*heaviside(t-0.375) - 2*heaviside(t-0.625) + 2*heaviside(t-0.875) - heaviside(t-1);
>> x6 = @(t) heaviside(t) - 2*heaviside(t-0.125) + 2*heaviside(t-0.375) - 2*heaviside(t-0.5) + 2*heaviside(t-0.625) -  2*heaviside(t-0.875) + heaviside(t-1);
>> x7 = @(t) heaviside(t) - 2*heaviside(t-0.125) + 2*heaviside(t-0.25) - 2*heaviside(t-0.375) + 2*heaviside(t-0.625) - 2*heaviside(t-0.75) + 2*heaviside(t-0.875) - heaviside(t-1);
>> x8 = @(t) heaviside(t) - 2*heaviside(t-0.125) + 2*heaviside(t-0.25) - 2*heaviside(t-0.375) + 2*heaviside(t-0.5) - 2*heaviside(t-0.625) + 2*heaviside(t-0.75) - 2*heaviside(t-0.875) + heaviside(t-1);
>>
>>
>> y = @(t) (27*t - 2).*(heaviside(t) - heaviside(t-1));
>> yh = @(t) (23/2).*(x1(t)) + (-27/2).*(x2(t)) + (-19/8).*(x4(t)) + (-195/16).*(x7(t)) + (-27/16).*(x8(t));
>> t = [0:0.01:1];
>> hold on
>> plot(t,y(t),'--b');
>> plot(t,yh(t),'r');
>> legend('y(t)', 'yh(t)', 'Location', 'SouthEast');
>> title('Part D');