Question

Find all the zeros of each equation.

7x^2 – 144 = –x^4



3, –3, 4i, 0
3, 4i
3, –3, 4i, –4i
–3, –4i

Answer 1

what ?

Answer 2

x^4 + 7x^2 - 144 = 0
x^4 + 16x^2 - 9x^2 - 144 = 0
x^2(x^2 + 16) - 9(x^2 + 16) = 0
(x^2 + 16) (x^2 - 9) = 0

x^2 + 16 = 0
x^2 - 9 = 0

x^2 = -16
x^2 = 9

x = + or - 4i
x = + or - 3

So the four solutions are:

x = {-4i, 4i, -3, 3}

Answer 3

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