Question

Express 21 = 10(cos(270°) + i sin(270)] in rectangular form.Express your answer in exact terms.mm

Answer 1

we have the expression

z1=10[cos(270)+isin(270)

see the attached figure to better understand the problem

we have that

cos(270)=0

sin(270)=-1

so

substitute

z1=10[0+i(-1)]

Z1=10[0-i]

z1=0-10i

therefore

rectangular form (0,-10i)