For the following 4 transfer functions, calculate the roots and based on the roots plot the response to a step response. This is supposed to be a pen and paper exercise close to how I solved a similar problem in class. 1. G(s)=s2+12s+400400 2. G(s)=s2+90s+900900 3. G(s)=s2+30s+225225 4. G(s)=s2+625625