Respuesta :
Answer:
1) [tex]x=1+i[/tex] and [tex]x=1-i[/tex] are the roots of the given quadratic equation.
2) [tex]x=(2i)^4=16[/tex]
Therefore x=2i,2i,2i,2i are the roots of the given number 16 and they are complex numbers too
Step-by-step explanation:
1) Given quadratic expression is [tex]x^2-2x+2[/tex]
First equate the given expression to zero then we will find the roots.
Since the given equation is quadratic hence it has two roots.
To find the roots of the given quadratic equation :
For the quadratic equation we have that [tex]ax^2+bx+c=0[/tex]
Therefore roots [tex]x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}[/tex] here a and b are coefficients of [tex]x^2andx[/tex] respectively and c is a constant
[tex]x^2-2x+2=0[/tex] here a=1 ,b=-2 and c=2
Now Substitute the values in [tex]x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}[/tex] we get
[tex]x=\frac{-(-2)\pm \sqrt{(-2)^2-4(1)(2)}}{2(1)}[/tex]
[tex]=\frac{2\pm \sqrt{4-8}}{2}[/tex]
[tex]=\frac{2\pm \sqrt{-4}}{2}[/tex]
[tex]=\frac{2\pm \sqrt{4i^2}}{2}[/tex]
[tex]=\frac{2\pm2i}{2}[/tex]
[tex]=2(\frac{1\pm i}{2})[/tex]
[tex]x=1\pm i[/tex]
Therefore [tex]x=1+i[/tex] and [tex]x=1-i[/tex] are the roots of the given quadratic equation.
2) Given that the number 16 has four roots.In other words, there are four complex numbers that can be entered in the square .
Let x be the given number 16
i.e., x=16
- From the given we can write [tex]x^4=16[/tex]
- Since the number has complex number as its roots
- Therefore we can write [tex]x^4=(2i)^4[/tex] as below
[tex]=2^4i^4[/tex] ( by using the formula [tex](ab)^m=a^mb^m[/tex] )
[tex]=16(1)[/tex] ( by [tex]i^2=-1[/tex] and [tex]i^4=(i^2)^2=(-1)^2=1[/tex] )
[tex]x^4=16=(2i)^4[/tex]
Therefore [tex]x^4=(2i)^4[/tex]
Since powers are same we can equate the bases ( bases are equal )
Therefore x=2i,2i,2i,2i are the roots of the given number 16 and they are complex numbers too
