# Sample exam questions

### Test Your MATLAB Knowledge for the MathWorks Certified MATLAB Associate Exam

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)