/ ____________\ / ____________\ / ______________\ / ______________\
| / ____ | | / ____ | | / ____ | | / ____ |
| / 1 \/ 17 | | / 1 \/ 17 | | / 1 \/ 17 | | / 1 \/ 17 |
|t + I* / - + ------ |*|t - I* / - + ------ |*|t + / - - + ------ |*|t - / - - + ------ |
\ \/ 2 2 / \ \/ 2 2 / \ \/ 2 2 / \ \/ 2 2 /
$$\left(t - i \sqrt{\frac{1}{2} + \frac{\sqrt{17}}{2}}\right) \left(t + i \sqrt{\frac{1}{2} + \frac{\sqrt{17}}{2}}\right) \left(t + \sqrt{- \frac{1}{2} + \frac{\sqrt{17}}{2}}\right) \left(t - \sqrt{- \frac{1}{2} + \frac{\sqrt{17}}{2}}\right)$$
(((t + i*sqrt(1/2 + sqrt(17)/2))*(t - i*sqrt(1/2 + sqrt(17)/2)))*(t + sqrt(-1/2 + sqrt(17)/2)))*(t - sqrt(-1/2 + sqrt(17)/2))
The perfect square
Let's highlight the perfect square of the square three-member
$$\left(t^{4} + t^{2}\right) - 4$$
To do this, let's use the formula
$$a t^{4} + b t^{2} + c = a \left(m + t^{2}\right)^{2} + n$$
where
$$m = \frac{b}{2 a}$$
$$n = \frac{4 a c - b^{2}}{4 a}$$
In this case
$$a = 1$$
$$b = 1$$
$$c = -4$$
Then
$$m = \frac{1}{2}$$
$$n = - \frac{17}{4}$$
So,
$$\left(t^{2} + \frac{1}{2}\right)^{2} - \frac{17}{4}$$