Question

simplify the number using the imaginary unit i: (square root) -28 options: a. 2(square root) -7 b. -2(square root) -7 c. i(square root) 28 d. 2i(square root) 28

Answer 1

`√(-28)=√(-4\cdot7)=√(-4)\cdot\sqrt7=2i\sqrt7`


`√(-28)=√(4\cdot(-7))=\sqrt4\cdot√(-7)=\boxed{2√(-7)}\to\fbox{a.}`