A quadratic function f(x) attains a maximum of 3 at x = 1. The value o...
We have f(x)=ax^2+bx+cf(x)=ax^2+bx+c.
f(0)=c=1f(0)=c=1 --> f(x)=ax^2+bx+1f(x)=ax^2+bx+1
We are told that fmax(1)=a+b+1=3
, --> a+b=2.
fmax is vertex of parabola and the x coordinate of vertex is
−b/2a=1−b2a=1
--> b=−2a
--> a+b=a
−2a=−a + b =a−2a=
−a=2 --> a=−2a=−2 and b=4b=4.
f(x)=−2x^2+4x+1 =f(x)=−2x^2+4x+1 --> f(10)=−200+40+1=−159
View all questions of this test
A quadratic function f(x) attains a maximum of 3 at x = 1. The value o...
Given information:
- The quadratic function f(x) attains a maximum of 3 at x = 1.
- The value of the function at x = 0 is 1.
To find:
The value of f(x) at x = 10.
Solution:
To find the value of f(x) at x = 10, we need to determine the equation of the quadratic function first.
Step 1: Determine the vertex form of the quadratic function.
The vertex form of a quadratic function is given by f(x) = a(x - h)^2 + k, where (h, k) represents the vertex of the parabola.
Given that the maximum value of f(x) is 3 at x = 1, we can determine the vertex of the parabola using the formula h = -b/2a, where a and b are coefficients of the quadratic function.
Since the maximum value occurs at x = 1, the vertex form can be written as:
f(x) = a(x - 1)^2 + 3
Step 2: Use the given information to find the equation of the quadratic function.
We are given that f(0) = 1. Substituting x = 0 in the equation of the quadratic function, we have:
1 = a(0 - 1)^2 + 3
1 = a + 3
a = -2
Therefore, the equation of the quadratic function is:
f(x) = -2(x - 1)^2 + 3
Step 3: Find the value of f(x) at x = 10.
Substituting x = 10 in the equation of the quadratic function, we have:
f(10) = -2(10 - 1)^2 + 3
f(10) = -2(9)^2 + 3
f(10) = -2(81) + 3
f(10) = -162 + 3
f(10) = -159
Therefore, the value of f(x) at x = 10 is -159.
Hence, the correct answer is option B) -159.