Polar & rectangular forms of complex numbers

Problem

Express z, start subscript, 1, end subscript, equals, 14, open bracket, cosine, left parenthesis, start fraction, pi, divided by, 2, end fraction, right parenthesis, plus, i, sine, left parenthesis, start fraction, pi, divided by, 2, end fraction, right parenthesis, close bracket in rectangular form.
Express your answer in exact terms.
z, start subscript, 1, end subscript, equals
Do 4 problems