we know that i=√-1 so we do pemdas [tex] \frac{1}{2} i[/tex]=[tex] \frac{ \sqrt{-1} }{2} [/tex] exponents [tex]( \frac{ \sqrt{-1} }{2} )^{2}= \frac{( \sqrt{-1} )^{2}}{2^{2}} [/tex]=[tex] \frac{-1}{4} [/tex] then [tex] (-2i)^{2} [/tex]=-2 times -2 times i times i=4 times -1=-4 now we have
