How do you multiply # (2 + i sqrt3)^2#? Precalculus Complex Numbers in Trigonometric Form Multiplication of Complex Numbers 1 Answer Konstantinos Michailidis Mar 28, 2016 Assuming that #i# is the imaginary unit we have that #(2+isqrt3)*(2+isqrt3)=2*2+2isqrt3+2isqrt3+(isqrt3)*(isqrt3)= 4+4isqrt3-3=1+4isqrt3# Finally #(2+isqrt3)^2=1+4isqrt3# Answer link Related questions How do I multiply complex numbers? How do I multiply complex numbers in polar form? What is the formula for multiplying complex numbers in trigonometric form? How do I use the modulus and argument to square #(1+i)#? What is the geometric interpretation of multiplying two complex numbers? What is the product of #3+2i# and #1+7i#? How do I use DeMoivre's theorem to solve #z^3-1=0#? How do I find the product of two imaginary numbers? How do you simplify #(2+4i)(2-4i)#? How do you multiply #(-2-8i)(6+7i)#? See all questions in Multiplication of Complex Numbers Impact of this question 1624 views around the world You can reuse this answer Creative Commons License