Solution:
The standard form of a quadratic equation is ax2 + bx + c = 0
The nature of the quadratic roots is determined by the discriminant.
Discriminant is written as Δ = b2 - 4ac
Given: -x2 + 4x - 2 = 0
Where a = -1, b = 4, c = -2
Substituting the values in the discriminant formula, we get
Δ = 42 - 4 × -1 × -2
By further calculation
Δ = 16 - 8
Δ = 8
Therefore, the discriminant is 8.
What is the discriminant of the quadratic equation -x2 + 4x - 2 = 0?
Summary:
The discriminant of the quadratic equation -x2 + 4x - 2 = 0 is 8.
The discriminant #Delta# characterize your solutions.
The discriminant #Delta# is a number that allows you to find out what type of solutions your equation will have.
1] If the discriminant is positive you'll have 2 separate real solutions #x_1!=x_2#;
2] If the discriminant is equal to zero you'll have 2 coincident real solutions, #x_1=x_2# (=two equal numbers...I know it is weird but do not worry);
3] If the discriminant is negative you'll have two complex solutions (in this case, at least for now, you stop and say that there will not be REAL solutions).
The discriminant is given as:
#color(red)(Delta=b^2-4ac)# where the letters can be found writing your equation in the general form:
#ax^2+bx+c=0# or in your case:
#x^2-4x+4=0#
so:
#a=1#
#b=-4#
#c=4#
and #Delta=(-4)^2-4(1*4)=16-16=0#
So you have case 2] two coincident solutions (if you solve your equation you'll find that it is satisfied by #x_1=x_2=2#).
Algebra Examples
Popular Problems
Algebra
Find the Discriminant x^2-4x-2=0
Step 1
The discriminant of a quadratic is the expression inside the radical of the quadratic formula.
Step 2
Substitute in the values of , , and .
Step 3
Evaluate the result to find the discriminant.
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Simplify each term.
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Raise to the power of .
Multiply .
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Multiply by .
Multiply by .
Add and .
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Find the discriminant of the quadratic equation. $-2-x^{2}=4 x^{2}$
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Video Transcript
This is a problem that wants us to find it. The equation has a number of coefficients. This is negative. T minus square. There are Pickles for an expert. In order to solve this one, I'm going to square X to both sides and add two signs. We're going to get five X squared by that. Zero is the number of plus two. Nope, it's in standard form. We can use our discriminative for formula of B squared minus for a C plugging in our values for A B and C will get zero squared. Negative four times five times two and minus four times five times two are negative 40. So are discriminated for. The equation is just negative A number 40. Thank you for that.
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