Answer fast pls When f(x) =x^4-2x^3+3x^2-ax+b is divided by ( x+1)and ...
When f(x) is divided by (x+1) and (x-1) , the remainders are 19 and 5 respectively .
∴ f(-1) = 19 and f(1) = 5
⇒ (-1)4 - 2 (-1)3 + 3(-1)2 - a (-1) + b = 19
⇒ 1 +2 + 3 + a + b = 19
∴ a + b = 13 ------- (i)
Again , f(1) = 5
⇒ 14 - 2 x 13 + 3 x 12 - a x 1 b = 5
⇒ 1 - 2 + 3 - a + b = 5
∴ b - a = 3 ------ (ii)
solving eqn (i) and (ii) , we get
a = 5 and b = 8
Now substituting the values of a and b in f(x) , we get
∴ f(x) = x4 - 2x3 + 3x2 - 5x + 8
Now f(x) is divided by (x-3) so remainder will be f(3)
∴ f(x) = ∴ f(x) = x4 - 2x3 + 3x2 - 5x + 8
⇒ f(3) = 34 - 2 x 33 + 3 x 32 - 5 x 3 + 8
= 81 - 54 + 27 - 15 + 8 = 47
This question is part of UPSC exam. View all Class 9 courses
Answer fast pls When f(x) =x^4-2x^3+3x^2-ax+b is divided by ( x+1)and ...
Remainder when f(x) is divided by x - 3
To find the remainder when f(x) is divided by x - 3, we can use the Remainder Theorem. According to the Remainder Theorem, if a polynomial f(x) is divided by x - c, the remainder is equal to f(c).
Given that the remainder when f(x) is divided by (x - 1) is 5, we have f(1) = 5. Similarly, the remainder when f(x) is divided by (x + 1) is 19, so f(-1) = 19.
Using the Remainder Theorem:
To find the remainder when f(x) is divided by x - 3, we need to evaluate f(3).
So, let's substitute x = 3 into the polynomial f(x) = x^4 - 2x^3 + 3x^2 - ax + b:
f(3) = (3)^4 - 2(3)^3 + 3(3)^2 - a(3) + b
Simplifying further:
f(3) = 81 - 54 + 27 - 3a + b
f(3) = 54 - 3a + b
Using the given remainders:
We know that f(1) = 5 and f(-1) = 19. Let's substitute these values into the equation we obtained for f(3):
54 - 3a + b = 5 ... (1)
54 - 3a + b = 19 ... (2)
Solving the equations:
Now, we have two equations with two unknowns (a and b). We can solve these equations simultaneously to find the values of a and b.
Subtracting equation (2) from equation (1), we get:
5 - 19 = 54 - 54 - 3a + 3a + b - b
-14 = 0
The equation -14 = 0 is not possible, meaning there is no solution for this system of equations. This implies that there is no unique value for the remainder when f(x) is divided by x - 3.
Therefore, the remainder when f(x) is divided by x - 3 is indeterminate or cannot be determined.
Note: It is important to double-check the given information to ensure that there are no errors or inconsistencies in the problem statement.
To make sure you are not studying endlessly, EduRev has designed Class 9 study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Class 9.