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1.5 Is there a range of timestep choices At where the solution is unstable (oscillating up and down rather than growing steadily)? You may find this easiest to see looking at the plots. If so, what values of At does this apply for? 1.6 Is there a range of timestep choices At where the error is roughly proportional to At? If so, what values of At does this apply for? What is the explanation for this? 1.7 Is there a range of timestep choices At where the error consistently does not improve even as n gets larger and At gets smaller? If so, what values of At does this apply for? What is the explanation for this