Thank you so much for telling me the meaning of imaginary root

Thank you so much for telling me the meaning of imaginary root

In mathematics, if a few squares are negative, that number is imaginary; all imaginary numbers are plural. The term "imaginary number" was coined by Descartes, a famous mathematician in the 17th century, because the idea at that time was that it was a real non-existent number, Every imaginary number can be expressed as IB, where B is a real number and I is defined as I ^ 2 = - 1
The imaginary roots include the roots of equations with imaginary units, that is, the roots of equations with negative square roots
For example:
①x^2+1=0
x^2=-1
X = ± I (imaginary root)
②x^3=1
x^3-1=0
（-1+x）（1+x+x^2）=0
X = 1, - 0.5 + √ 3I / 2 or - 0.5 - √ 3I / 2
(conjugate complex root)
③cosx=2
x=1.316957897i
(trigonometric functions extended to complex numbers)