√42 -- 6.48074069841
√150 -- 12.2474487139
√245 -- 15.6524758425
√398 -- 19.9499373433
Hope it helps... pls mark brainliest
Note that if a + bi is a root of P(x) = 0, then a – bi is also a root of P(x) = 0.
In this case, i and 7 + 8i are two roots of P(x) = 0. So –i and 7 – 8i are two additional roots of P(x) = 0.