Answer: 8 i
Step-by-step explanation: The square root of negative 64 is 8 i. Whenever you are finding a negative square root you need to find what times what will equal that number. 8 x 8 = 64. So the square root is 8. But, since we are finding a negative square root, the answer will be 8 i. i states that 8 is the negative square root of 64.
So the answer is 8 i.
Always add i after the number when finding negative square roots.