Home
Class 11
MATHS
Statement-1: If a, b, c, A, B, C are rea...

Statement-1: If a, b, c, A, B, C are real numbers such that `a lt b lt c`, then `f(x) = (x-a)(x-b)(x-c) -A^(2)(x-a)-B^(2)(x-b)-C^(2)(x-c)` has exactly one real root.
Statement-2: If f(x) is a real polynomical and `x_(1), x_(2) in R` such that `f(x_(1)) f(x_(2)) lt 0`, then f(x) has at least one real root between `x_(1) and x_(2)`

A

Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1.

B

Statement-1 is True, Statement-2 is True, Statement-2 is not a correct explanation for Statement-1.

C

Statement-1 is True, Statement-2 is False.

D

Statement-1 is False, Statement-2 is True.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze both statements provided in the question. ### Step 1: Analyze Statement 2 **Statement 2:** If \( f(x) \) is a real polynomial and \( x_1, x_2 \in \mathbb{R} \) such that \( f(x_1) f(x_2) < 0 \), then \( f(x) \) has at least one real root between \( x_1 \) and \( x_2 \). **Solution:** 1. Since \( f(x) \) is a polynomial, it is continuous. 2. If \( f(x_1) f(x_2) < 0 \), it means one of the values is positive and the other is negative. 3. By the Intermediate Value Theorem, since \( f(x) \) is continuous, there must be at least one point \( c \) in the interval \( (x_1, x_2) \) where \( f(c) = 0 \). 4. Therefore, Statement 2 is **true**. ### Step 2: Analyze Statement 1 **Statement 1:** If \( a < b < c \), then \( f(x) = (x-a)(x-b)(x-c) - A^2(x-a) - B^2(x-b) - C^2(x-c) \) has exactly one real root. **Solution:** 1. First, observe the function \( f(x) \): \[ f(x) = (x-a)(x-b)(x-c) - A^2(x-a) - B^2(x-b) - C^2(x-c) \] 2. Evaluate \( f(a) \): \[ f(a) = (a-a)(a-b)(a-c) - A^2(a-a) - B^2(a-b) - C^2(a-c) = 0 - 0 - B^2(a-b) - C^2(a-c) \] Since \( a < b < c \), \( f(a) \) is positive. 3. Evaluate \( f(c) \): \[ f(c) = (c-a)(c-b)(c-c) - A^2(c-a) - B^2(c-b) - C^2(c-c) = 0 - A^2(c-a) - B^2(c-b) \] Since \( a < b < c \), \( f(c) \) is negative. 4. Since \( f(a) > 0 \) and \( f(c) < 0 \), by the Intermediate Value Theorem, there is at least one root in the interval \( (a, c) \). 5. Next, we need to check if there are more than one root. The polynomial \( (x-a)(x-b)(x-c) \) is a cubic polynomial, which can have up to three roots. The additional terms \( -A^2(x-a) - B^2(x-b) - C^2(x-c) \) can modify the behavior of the function, but they do not guarantee that there will only be one root. 6. Thus, it is possible for \( f(x) \) to have more than one real root, contradicting the claim of Statement 1. Therefore, Statement 1 is **false**. ### Conclusion - Statement 1 is **false**. - Statement 2 is **true**. Thus, the correct answer is **Option D**: Statement 1 is false, and Statement 2 is true.

To solve the problem, we need to analyze both statements provided in the question. ### Step 1: Analyze Statement 2 **Statement 2:** If \( f(x) \) is a real polynomial and \( x_1, x_2 \in \mathbb{R} \) such that \( f(x_1) f(x_2) < 0 \), then \( f(x) \) has at least one real root between \( x_1 \) and \( x_2 \). **Solution:** 1. Since \( f(x) \) is a polynomial, it is continuous. 2. If \( f(x_1) f(x_2) < 0 \), it means one of the values is positive and the other is negative. ...
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • QUADRATIC EXPRESSIONS AND EQUATIONS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Exercise|138 Videos
  • QUADRATIC EXPRESSIONS AND EQUATIONS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|50 Videos
  • QUADRATIC EXPRESSIONS AND EQUATIONS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Section I - Solved Mcqs|123 Videos
  • PROBABILITY

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|45 Videos
  • SEQUENCES AND SERIES

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|59 Videos

Similar Questions

Explore conceptually related problems

Statement-1: If alpha and beta are real roots of the quadratic equations ax^(2) + bx + c = 0 and -ax^(2) + bx + c = 0 , then (a)/(2) x^(2) + bx + c = 0 has a real root between alpha and beta Statement-2: If f(x) is a real polynomial and x_(1), x_(2) in R such that f(x_(1)) f_(x_(2)) lt 0 , then f(x) = 0 has at leat one real root between x_(1) and x_(2) .

Statement-1: The equation (pi^(e))/(x-e)+(e^(pi))/(x-pi)+(pi^(pi)+e^(e))/(x-pi-e) = 0 has real roots. Statement-2: If f(x) is a polynomial and a, b are two real numbers such that f(a) f(b) lt 0 , then f(x) = 0 has an odd number of real roots between a and b.

If a , b , c , are real number such that a c!=0, then show that at least one of the equations a x^2+b x+c=0 and -a x^2+b x+c=0 has real roots.

Statement-1: If a, b, c in R and 2a + 3b + 6c = 0 , then the equation ax^(2) + bx + c = 0 has at least one real root in (0, 1). Statement-2: If f(x) is a polynomial which assumes both positive and negative values, then it has at least one real root.

Statement-1: If a, b, c are distinct real numbers, then a((x-b)(x-c))/((a-b)(a-c))+b((x-c)(x-a))/((b-c)(b-a))+c((x-a)(x-b))/((c-a)(c-b))=x for each real x. Statement-2: If a, b, c in R such that ax^(2) + bx + c = 0 for three distinct real values of x, then a = b = c = 0 i.e. ax^(2) + bx + c = 0 for all x in R .

Statement -1 : one root of the equation x^(2)+5x-7=0 lie in the interval (1,2). and Statement -2 : For a polynomial f(x),if f(p)f(q) lt 0, then there exists at least one real root of f(x) =0 in (p,q)

Let f(x)=a sin x+c , where a and c are real numbers and a>0. Then f(x)lt0, AA x in R if

Statement-1: Let a,b,c be non zero real numbers and f(x)=ax^2+bx+c satisfying int_0^1 (1+cos^8x)f(x)dx=int_0^2(1+cos^8x)f(x)dx then the equation f(x)=0 has at least one root in (0,2) .Statement-2: If int_a^b g(x)dx vanishes and g(x) is continuous then the equation g(x)=0 has at least one real root in (a,b) . (A) Both 1 and 2 are true and 2 is the correct explanation of 1 (B) Both 1 and 2 are true and 2 is not correct explanation of 1 (C) 1 is true but 2 is false (D) 1 is false but 2 is true

If a lt b lt c , then find the range of f(x)="|x-a|+|x-b|+|x-c|

Statement 1 The equation a^(x)+b^(x)+c^(x)-d^(x)=0 has only real root, if agtbgtcgtd . Statement 2 If f(x) is either strictly increasing or decreasing function, then f(x)=0 has only real root.