If the quadratic polynomials defined on real coefficient
`P(x)=a_(1)x^(2)+2b_(1)x+c_(1)` and `Q(x)=a_(2)x^(2)+2b_(2)x+c_(2)` take positive values `AA x in R`, what can we say for the trinomial `g(x)=a_(1)a_(2)x^(2)+b_(1)b_(2)x+c_(1)c_(2)` ?
If the quadratic polynomials defined on real coefficient
`P(x)=a_(1)x^(2)+2b_(1)x+c_(1)` and `Q(x)=a_(2)x^(2)+2b_(2)x+c_(2)` take positive values `AA x in R`, what can we say for the trinomial `g(x)=a_(1)a_(2)x^(2)+b_(1)b_(2)x+c_(1)c_(2)` ?
`P(x)=a_(1)x^(2)+2b_(1)x+c_(1)` and `Q(x)=a_(2)x^(2)+2b_(2)x+c_(2)` take positive values `AA x in R`, what can we say for the trinomial `g(x)=a_(1)a_(2)x^(2)+b_(1)b_(2)x+c_(1)c_(2)` ?
A
`g(x)` takes positive values only.
B
`g(x)` takes negative values only.
C
`g(x)` can takes positive as well as negative values.
D
Nothing definite can be said about `g(x)`.
Text Solution
AI Generated Solution
The correct Answer is:
To solve the problem, we need to analyze the given quadratic polynomials \( P(x) \) and \( Q(x) \) and their properties, and then determine the behavior of the trinomial \( g(x) \).
### Step 1: Analyze the Quadratic Polynomials
The polynomials are given as:
\[
P(x) = a_1 x^2 + 2b_1 x + c_1
\]
\[
Q(x) = a_2 x^2 + 2b_2 x + c_2
\]
Since both \( P(x) \) and \( Q(x) \) take positive values for all \( x \in \mathbb{R} \), we can conclude that:
1. The leading coefficients \( a_1 \) and \( a_2 \) must be positive (i.e., \( a_1 > 0 \) and \( a_2 > 0 \)).
2. The discriminants of both polynomials must be negative.
### Step 2: Calculate the Discriminants
The discriminant \( D \) of a quadratic polynomial \( ax^2 + bx + c \) is given by \( D = b^2 - 4ac \).
For \( P(x) \):
\[
D_1 = (2b_1)^2 - 4a_1c_1 = 4b_1^2 - 4a_1c_1 < 0 \implies b_1^2 < a_1c_1 \quad \text{(Equation 1)}
\]
For \( Q(x) \):
\[
D_2 = (2b_2)^2 - 4a_2c_2 = 4b_2^2 - 4a_2c_2 < 0 \implies b_2^2 < a_2c_2 \quad \text{(Equation 2)}
\]
### Step 3: Multiply the Inequalities
From Equation 1 and Equation 2, we multiply both sides:
\[
(b_1^2)(b_2^2) < (a_1c_1)(a_2c_2)
\]
This gives us:
\[
a_1a_2c_1c_2 > b_1^2b_2^2
\]
### Step 4: Analyze the Trinomial \( g(x) \)
The trinomial is defined as:
\[
g(x) = a_1a_2x^2 + b_1b_2x + c_1c_2
\]
We need to find the discriminant of \( g(x) \):
\[
D_g = (b_1b_2)^2 - 4(a_1a_2)(c_1c_2)
\]
Substituting from our previous result:
\[
D_g = b_1^2b_2^2 - 4a_1a_2c_1c_2
\]
Using the inequality we derived:
\[
D_g < b_1^2b_2^2 - 4b_1^2b_2^2 = -3b_1^2b_2^2
\]
Since \( b_1^2b_2^2 > 0 \), it follows that:
\[
D_g < 0
\]
### Step 5: Conclusion
Since the discriminant \( D_g \) is negative, the trinomial \( g(x) \) has no real roots, and because the leading coefficient \( a_1a_2 > 0 \), it implies that \( g(x) \) takes positive values for all \( x \in \mathbb{R} \).
Thus, the answer is:
**Option A: \( g(x) \) takes positive values only.**
To solve the problem, we need to analyze the given quadratic polynomials \( P(x) \) and \( Q(x) \) and their properties, and then determine the behavior of the trinomial \( g(x) \).
### Step 1: Analyze the Quadratic Polynomials
The polynomials are given as:
\[
P(x) = a_1 x^2 + 2b_1 x + c_1
\]
\[
...
Topper's Solved these Questions
Similar Questions
Explore conceptually related problems
If two equation a_(1) x^(2) + b_(1) x + c_(1) = 0 and, a_(2) x^(2) + b_(2) x + c_(2) = 0 have a common root, then the value of (a_(1) b_(2) - a_(2) b_(1)) (b_(1) c_(2) - b_(2) c_(1)) , is
If the lines x=a_(1)y + b_(1), z=c_(1)y +d_(1) and x=a_(2)y +b_(2), z=c_(2)y + d_(2) are perpendicular, then
Statement - 1 : For the straight lines 3x - 4y + 5 = 0 and 5x + 12 y - 1 = 0 , the equation of the bisector of the angle which contains the origin is 16 x + 2 y + 15 = 0 and it bisects the acute angle between the given lines . statement - 2 : Let the equations of two lines be a_(1) x + b_(1) y + c_(1) = 0 and a_(2) x + b_(2) y + c_(2) = 0 where c_(1) and c_(2) are positive . Then , the bisector of the angle containing the origin is given by (a_(1) x + b_(1) y + c_(1))/(sqrt(a_(2)^(2) + b_(1)^(2))) = (a_(2) x + b_(2)y + c_(2))/(sqrt(a_(2)^(2) + b_(2)^(2))) If a_(1) a_(2) + b_(1) b_(2) gt 0 , then the above bisector bisects the obtuse angle between given lines .
Find the condition for two lines a_(1)x+b_(1)y+c_(1)=0 and a_(2)x+b_(2)y+c_(2)=0 to be (i) parallel (ii) perpendicular
Given a_(i)^(2) + b_(i)^(2) + c_(i)^(2) = 1, i = 1, 2, 3 and a_(i) a_(j) + b_(i) b_(j) + c_(i) c_(j) = 0 (i !=j, i, j =1, 2, 3) , then the value of the determinant |(a_(1),a_(2),a_(3)),(b_(1),b_(2),b_(3)),(c_(1),c_(2),c_(3))| , is
If (x - a) be a factor common to a_(1)x^(2) + b_(1)x +c and a_2x^2 + b_(2)x + c , then prove that: alpha(a_(1)-a_(2))=b_(2)-b_(1)
The asymptotes of the hyperbola (x^(2))/(a_(1)^(2))-(y^(2))/(b_(1)^(2))=1 and (x^(2))/(a_(2)^(2))-(y^(2))/(b_(2)^(2))=1 are perpendicular to each other. Then, (a) a_(1)/a_(2)=b_(1)/b_(2) (b) a_(1)a_(2)=b_(1)b_(2) (c) a_(1)a_(2)+b_(1)b_(2)=0 (d) a_(1)-a_(2)=b_(1)-b_(2)
Let n be positive integer such that, (1+x+x^(2))^(n)=a_(0)+a_(1)x+a_(2)x^(2)+….+a_(2n)x^(2n) , then a_(r) is :
If two circles x^(2)+y^(2)+2a_(1)x+2b_(1)y=0 and x^(2)+y^(2)+2a_(2)x+2b_(2)y=0 touches then show that a_(1)b_(2)=a_(2)b_(1)
If the expansion in power of x of the function (1)/(( 1 - ax)(1 - bx)) is a_(0) + a_(1) x + a_(2) x^(2) + a_(3) x^(3) + …, then a_(n) is