Respuesta :
Answer:
x=(5+i*sqrt(35))/2, (5-i*sqrt(35))/2
Step-by-step explanation:
Use the quadratic formula with the following values.
a = 1
b = -5
c = 15
Substitute and simplify.
(5+-sqrt((-5)^2-4*(1*15)))/2*1
x = (5+-i*sqrt(35))/2
When you get a negative number inside the square root, remember that you can pull out i to make the number inside positive.
ANSWER
[tex]x = \frac{5}{2} - \frac{ \sqrt{35}i }{2} \: or \: x = \frac{5}{2} + \frac{ \sqrt{35}i }{2} [/tex]
EXPLANATION
The given equation is
[tex]y = {x}^{2} - 5x + 15[/tex]
To solve this equation, we equate it to zero.
[tex]{x}^{2} - 5x + 15 = 0[/tex]
Comparing to ax²+bx+c=0, we have a=1, b=-5, c=15.
The solution is given by the quadratic formula,
[tex]x = \frac{ - b \pm \sqrt{ {b}^{2} - 4ac } }{2a} [/tex]
We plug in the values to obtain,
[tex]x = \frac{ - - 5\pm \sqrt{ {( - 5)}^{2} - 4(1)(15) } }{2(1)} [/tex]
[tex]x = \frac{5\pm \sqrt{ 25 -60 }}{2} [/tex]
[tex]x = \frac{5\pm \sqrt{ - 35}}{2} [/tex]
Recall that,
[tex]\sqrt{-1}=i[/tex]
[tex]x = \frac{5\pm \sqrt{ 35}i}{2} [/tex]
[tex]x = \frac{5}{2} - \frac{ \sqrt{35}i }{2} \: or \: x = \frac{5}{2} + \frac{ \sqrt{35}i }{2} [/tex]
[tex]x = \frac{5}{2} - \frac{ \sqrt{35}i }{2} \: or \: x = \frac{5}{2} + \frac{ \sqrt{35}i }{2} [/tex]
EXPLANATION
The given equation is
[tex]y = {x}^{2} - 5x + 15[/tex]
To solve this equation, we equate it to zero.
[tex]{x}^{2} - 5x + 15 = 0[/tex]
Comparing to ax²+bx+c=0, we have a=1, b=-5, c=15.
The solution is given by the quadratic formula,
[tex]x = \frac{ - b \pm \sqrt{ {b}^{2} - 4ac } }{2a} [/tex]
We plug in the values to obtain,
[tex]x = \frac{ - - 5\pm \sqrt{ {( - 5)}^{2} - 4(1)(15) } }{2(1)} [/tex]
[tex]x = \frac{5\pm \sqrt{ 25 -60 }}{2} [/tex]
[tex]x = \frac{5\pm \sqrt{ - 35}}{2} [/tex]
Recall that,
[tex]\sqrt{-1}=i[/tex]
[tex]x = \frac{5\pm \sqrt{ 35}i}{2} [/tex]
[tex]x = \frac{5}{2} - \frac{ \sqrt{35}i }{2} \: or \: x = \frac{5}{2} + \frac{ \sqrt{35}i }{2} [/tex]