Join the IDNLearn.com community and get your questions answered by knowledgeable individuals. Ask your questions and get detailed, reliable answers from our community of experienced experts.

Which line will have no solution with the parabola [tex]y - x + 2 = x^2[/tex]?

Sagot :

To determine which line will have no solutions when intersecting the parabola given by the equation [tex]\( y - x + 2 = x^2 \)[/tex], we need to find a line such that the system of equations has no intersections. This involves considering the quadratic equation formed when substituting the line equation into the parabola equation.

### Step-by-Step Solution:

1. Rewrite the Parabola Equation:
[tex]\[ y - x + 2 = x^2 \implies y = x^2 + x - 2 \][/tex]

2. Consider the Line Equation:
[tex]\[ y = mx + c \][/tex]

3. Substitute the Line Equation into the Parabola Equation:
Substitute [tex]\( y = mx + c \)[/tex] into [tex]\( y = x^2 + x - 2 \)[/tex]:
[tex]\[ mx + c = x^2 + x - 2 \][/tex]

4. Form the Quadratic Equation:
Rearrange the equation to form a standard quadratic equation:
[tex]\[ x^2 + x - mx - 2 - c = 0 \implies x^2 + (1 - m)x - (2 + c) = 0 \][/tex]
This quadratic equation is of the form [tex]\( ax^2 + bx + c = 0 \)[/tex], where:
[tex]\[ a = 1, \quad b = 1 - m, \quad c = -(2 + c) \][/tex]

5. Compute the Discriminant:
The discriminant [tex]\( \Delta \)[/tex] of a quadratic equation [tex]\( ax^2 + bx + c = 0 \)[/tex] is given by:
[tex]\[ \Delta = b^2 - 4ac \][/tex]
Substitute [tex]\( a = 1 \)[/tex], [tex]\( b = 1 - m \)[/tex], and [tex]\( c = -(2 + c) \)[/tex] into the discriminant formula:
[tex]\[ \Delta = (1 - m)^2 - 4 \cdot 1 \cdot -(2 + c) = (1 - m)^2 + 4(2 + c) \][/tex]

6. Set the Discriminant to Be Less than Zero:
For the quadratic equation to have no real solutions, the discriminant must be less than zero:
[tex]\[ (1 - m)^2 + 4(2 + c) < 0 \][/tex]

7. Simplify the Inequality:
[tex]\[ (1 - m)^2 + 4(2 + c) < 0 \implies 1 - 2m + m^2 + 8 + 4c < 0 \implies m^2 - 2m + 9 + 4c < 0 \][/tex]

8. Solve for the Condition on [tex]\( c \)[/tex]:
[tex]\[ 4c < - (m^2 - 2m + 9) \implies 4c < - m^2 + 2m - 9 \implies c < \frac{- m^2 + 2m - 9}{4} \][/tex]

Thus, the line [tex]\( y = mx + c \)[/tex] will have no intersection with the parabola [tex]\( y - x + 2 = x^2 \)[/tex] if and only if the constant [tex]\( c \)[/tex] satisfies the inequality:
[tex]\[ c < \frac{- m^2 + 2m - 9}{4} \][/tex]