We are given a quadratic function $y = x^2 + (k+3)x + k+3$. We need to find the range of values for $k$ for which the quadratic function crosses the x-axis at two different points. This means that the quadratic equation $x^2 + (k+3)x + k+3 = 0$ has two distinct real roots.
2025/4/5
1. Problem Description
We are given a quadratic function . We need to find the range of values for for which the quadratic function crosses the x-axis at two different points. This means that the quadratic equation has two distinct real roots.
2. Solution Steps
For a quadratic equation to have two distinct real roots, the discriminant must be greater than zero. The discriminant is given by .
In our case, , , and . So the discriminant is:
We want , so we have:
We can factor out :
Now we need to find the values of that satisfy this inequality. We can analyze the sign of the expression by considering the intervals determined by the roots and .
Case 1: . In this case, both and are negative, so their product is positive.
Case 2: . In this case, is positive and is negative, so their product is negative.
Case 3: . In this case, both and are positive, so their product is positive.
We want , so we need either or .
3. Final Answer
The range of for which the quadratic function crosses the x-axis at two different points is or . In interval notation, this is .