engineering

Which command will return the corner elements of a 10-by-10 matrix A? A. A([1,end], [1,end]) B. A([1,1], [end,end]) C. A({[1,1], [1,end], [end,1], [end,end]}) D. A(1:end, 1:end) Which command will return the fraction of positive numbers in a 10-by-10 matrix A? A. A(A > 0)/A B. numel(A > 0)/numel(A) C. sum(A > 0)/prod(size(A)) D. nnz(A > 0)/numel(A) Which command will delete (completely remove) the last cell of a cell-array C? A. C{end} = []; B. C[end] = []; C. C(end) = []; D. C{end} = {[]}; Which command will create a plot of acceleration vs. time (i.e., a vector time on the x-axis and a vector acceleration on the y-axis)? A. plot(time, acceleration) B. plot(acceleration, time) C. plot([time, acceleration]) D. plot([acceleration, time]) Which command will give the standard deviation for each column in a 10-by-5 matrix Z? A. std(Z(:)) B. std(std(Z)) C. std(Z(1:5, :)) D. std(Z)