Which graph represents a phase shift of pi/2 units right for the graph of y=cos x

Solution:

we are given that

Here we are going to plot two curves one for cosx and the othere also of cosx but after making a phase shift of

When we do a phase shift by an angle of theta , in that case actaully we add angle negative theta .

For example when we shift the phase of sinx by we get  

Hence we are going to plot the curve of

Hence the correct option is B.