Lin decides to solve the equation using the quadratic formula. Here is her work:

x = -b ± √b²-4ac / 2a
x = -(-6) ± √(-6)²-4(1)(10) / 2(1)
x = 6 ± √36-40 / 2

Lin knows 36 – 40 is a negative number and isn't sure what to do next. Show how Lin can write her solution using i.