Respuesta :
Y = -3x-3 has one real solution.
Y= x^2 -3x + 5 has no real solutions because b^2 - 4ac, the discriminant, is less than zero.
Y= x^2 -3x + 5 has no real solutions because b^2 - 4ac, the discriminant, is less than zero.
To find the solutions to each equation, we'll first have to set Y to 0. We have:[tex]-3x-3 &=0\\ x^2-3x+5=0[/tex]
To obtain the solutions for both, you'll have to solve them for x. The first equation is linear, so obtaining a solution there is fairly straightforward, and you're guaranteed to get one real solution there. The second equation is a little more involved, and we'll need the quadratic formula to settle that one out. You might remember from earlier math classes that the quadratic formula gives you a way to quickly find the roots of a particular quadratic equation. Here's the full thing:
[tex]x= \frac{-b\pm\sqrt{b^2-4ac}}{2a} [/tex]
For the sake of this question, the only part we're concerned with is the [tex]b^2-4ac[/tex] bit, which is referred to as the descriminant of the quadratic. If [tex]b^2-4ac \geq 1[/tex], we'll have two real solutions, since we'll need to evaluate the square root of the term for both positive and negative outcomes. If [tex]b^2-4ac=0[/tex], we only have one real solution, since adding and subtracting 0 from the [tex]-b[/tex] term have the same effect. If [tex]b^2-4ac \ \textless \ 0[/tex], we have no real solutions; the discriminant is nested inside a square root, and taking the square root of a negative number only produces imaginary results.
With that in mind, let's look at the discriminant of [tex]x^2-3x+5[/tex].
Looking at the coefficients and constant, we have a=1, b=-3, and c=5, which makes our discriminant
[tex](-3)^2-4(1)(5) = 9-20=-11[/tex]
-11 is less than 0, so we have no real solutions to the second equation. This means that our first equation is the only one with a real solution, so the total number of real solutions for the system is 1.
To obtain the solutions for both, you'll have to solve them for x. The first equation is linear, so obtaining a solution there is fairly straightforward, and you're guaranteed to get one real solution there. The second equation is a little more involved, and we'll need the quadratic formula to settle that one out. You might remember from earlier math classes that the quadratic formula gives you a way to quickly find the roots of a particular quadratic equation. Here's the full thing:
[tex]x= \frac{-b\pm\sqrt{b^2-4ac}}{2a} [/tex]
For the sake of this question, the only part we're concerned with is the [tex]b^2-4ac[/tex] bit, which is referred to as the descriminant of the quadratic. If [tex]b^2-4ac \geq 1[/tex], we'll have two real solutions, since we'll need to evaluate the square root of the term for both positive and negative outcomes. If [tex]b^2-4ac=0[/tex], we only have one real solution, since adding and subtracting 0 from the [tex]-b[/tex] term have the same effect. If [tex]b^2-4ac \ \textless \ 0[/tex], we have no real solutions; the discriminant is nested inside a square root, and taking the square root of a negative number only produces imaginary results.
With that in mind, let's look at the discriminant of [tex]x^2-3x+5[/tex].
Looking at the coefficients and constant, we have a=1, b=-3, and c=5, which makes our discriminant
[tex](-3)^2-4(1)(5) = 9-20=-11[/tex]
-11 is less than 0, so we have no real solutions to the second equation. This means that our first equation is the only one with a real solution, so the total number of real solutions for the system is 1.