What is the square root of negative 4? Algebra Radicals and Geometry Connections Simplification of Radical Expressions 1 Answer George C. Jun 2, 2015 #-4# has two complex square roots, namely #+-2i# (where #i = sqrt(-1)#) Answer link Related questions How do you simplify radical expressions? How do you simplify radical expressions with fractions? How do you simplify radical expressions with variables? What are radical expressions? How do you simplify #root{3}{-125}#? How do you write # ""^4sqrt(zw)# as a rational exponent? How do you simplify # ""^5sqrt(96)# How do you write # ""^9sqrt(y^3)# as a rational exponent? How do you simplify #sqrt(75a^12b^3c^5)#? How do you simplify #sqrt(50)-sqrt(2)#? See all questions in Simplification of Radical Expressions Impact of this question 10489 views around the world You can reuse this answer Creative Commons License