@Arvind gupta ( 6269276247 )
the image is not clear, but from what i understood,
z ( ) = A + i B
now in this, A = |z| cos C and B = |z| sin C
if B = 0, which what it seem in picture, then C = 0 or .
C is amplitude of z.
i hope i have cleared your doubt, if you have some any other problem you can ask.
comp numStudy 40% syllabus and score up to 100% marks in JEE