For real values of `theta,` which of the following is/are always positive?

Which one of the following always be negative?

Which of the following is always free from viruses?

For all real values of theta , choose the correct options.

For a real object, which of the following can produce a real image?

If A(theta)=[(sin theta, i cos theta),(i cos theta, sin theta)] , then which of the following is not true ?

The true set of real values of x for which the function f(x)=xlnx-x+1 is positive is

In which of the following process, the process is always non-feasible?