To solve the problem, we need to determine the nature (sign) of the zeroes of the quadratic polynomial \( x^2 + 24x + 119 \).
1. Recall the standard form of a quadratic equation:
A quadratic polynomial can be written as:
\( ax^2 + bx + c \)
For our equation, \( a = 1 \), \( b = 24 \), and \( c = 119 \).
2. Find the discriminant:
The discriminant \( D \) of a quadratic equation is given by:
\( D = b^2 - 4ac \)
Substitute the values:
\( D = 24^2 - 4(1)(119) = 576 - 476 = 100 \)
Since \( D > 0 \), the roots are real and distinct.
3. Find the roots using factorization:
We need to find two numbers that multiply to 119 and add to 24.
The numbers are 17 and 7, so we can factor the equation as:
\( x^2 + 17x + 7x + 119 = 0 \)
\( x(x + 17) + 7(x + 17) = 0 \)
\( (x + 7)(x + 17) = 0 \)
Therefore, the roots are \( x = -7 \) and \( x = -17 \).
4. Determine the signs of the roots:
Both roots are negative.
Final Answer:
The correct answer is option (C): both negative.
For \( X = (x_1, x_2, x_3)^T \in \mathbb{R}^3 \), consider the quadratic form:
\[ Q(X) = 2x_1^2 + 2x_2^2 + 3x_3^2 + 4x_1x_2 + 2x_1x_3 + 2x_2x_3. \] Let \( M \) be the symmetric matrix associated with the quadratic form \( Q(X) \) with respect to the standard basis of \( \mathbb{R}^3 \).
Let \( Y = (y_1, y_2, y_3)^T \in \mathbb{R}^3 \) be a non-zero vector, and let
\[ a_n = \frac{Y^T(M + I_3)^{n+1}Y}{Y^T(M + I_3)^n Y}, \quad n = 1, 2, 3, \dots \] Then, the value of \( \lim_{n \to \infty} a_n \) is equal to (in integer).
If the given figure shows the graph of polynomial \( y = ax^2 + bx + c \), then: