Home
Class 12
MATHS
If f'(x) = g(x) (x-a)^2, where g(a) != 0...

If `f'(x) = g(x) (x-a)^2`, where g(a) `!= 0` and g is continuous at x = a, then :

A

f is increasing near a if `g(a) lt 0`

B

f is decreasing near a if ` g(a) gt 0`

C

f is decreasing near a if ` g(a) lt 0`

D

f is increasing near a if ` g(a) gt 0`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we start with the given information: 1. We have \( f'(x) = g(x) (x - a)^2 \). 2. It is given that \( g(a) \neq 0 \) and \( g \) is continuous at \( x = a \). ### Step 1: Analyze \( f'(x) \) Since \( f'(x) = g(x) (x - a)^2 \), we note that \( (x - a)^2 \) is always non-negative for all \( x \). This means that the sign of \( f'(x) \) is determined by the sign of \( g(x) \). ### Step 2: Evaluate \( g(a) \) Given that \( g(a) \neq 0 \), we have two cases to consider: - Case 1: \( g(a) > 0 \) - Case 2: \( g(a) < 0 \) ### Step 3: Case 1 - \( g(a) > 0 \) If \( g(a) > 0 \), and since \( g \) is continuous at \( x = a \), there exists a neighborhood around \( a \) where \( g(x) \) remains positive. Thus, in this neighborhood, \( f'(x) = g(x) (x - a)^2 > 0 \). This implies that \( f(x) \) is increasing near \( a \). ### Step 4: Case 2 - \( g(a) < 0 \) If \( g(a) < 0 \), and again using the continuity of \( g \) at \( x = a \), there exists a neighborhood around \( a \) where \( g(x) \) remains negative. Therefore, in this neighborhood, \( f'(x) = g(x) (x - a)^2 < 0 \). This implies that \( f(x) \) is decreasing near \( a \). ### Conclusion From our analysis, we conclude: - \( f(x) \) is increasing near \( a \) if \( g(a) > 0 \). - \( f(x) \) is decreasing near \( a \) if \( g(a) < 0 \). ### Final Answer Thus, the correct options are: 1. \( f \) is increasing near \( a \) if \( g(a) > 0 \). 2. \( f \) is decreasing near \( a \) if \( g(a) < 0 \).
Promotional Banner

Topper's Solved these Questions

  • APPLICATION OF DERIVATIVES

    AAKASH INSTITUTE ENGLISH|Exercise Assignment SECTION-D ( Linked Comprehension Type Questions )|3 Videos
  • APPLICATION OF DERIVATIVES

    AAKASH INSTITUTE ENGLISH|Exercise Assignment SECTION-E ( Assertion -Reason Type Questions )|4 Videos
  • APPLICATION OF DERIVATIVES

    AAKASH INSTITUTE ENGLISH|Exercise Assignment SECTION-C( Objective Type Questions ( More than one option are correct ))|1 Videos
  • APPLICATION OF INTEGRALS

    AAKASH INSTITUTE ENGLISH|Exercise Assignment Section - I Aakash Challengers Questions|2 Videos

Similar Questions

Explore conceptually related problems

If f^(prime)(x)=g(x)(x-a)^2,w h e r eg(a)!=0,a n dg is continuous at x=a , then (a) f is increasing in the neighbourhood of a if g(a)>0 (b) f is increasing in the neighbourhood of a if g(a) 0 (d) f is decreasing in the neighbourhood of a if g(a)<0

Given that f(x) = xg (x)//|x| g(0) = g'(0)=0 and f(x) is continuous at x=0 then the value of f'(0)

Let f(x) and g(x) be two equal real function such that f(x)=(x)/(|x|) g(x), x ne 0 If g(0)=g'(0)=0 and f(x) is continuous at x=0, then f'(0) is

Let f be a function such that f(x+y)=f(x)+f(y)" for all "x and y and f(x) =(2x^(2)+3x) g(x)" for all "x, " where "g(x) is continuous and g(0) = 3. Then find f'(x)

Let f be a function such that f(x+y)=f(x)+f(y) for all xa n dya n df(x)=(2x^2+3x)g(x) for all x , where g(x) is continuous and g(0)=3. Then find f^(prime)(x)dot

Let f be a function such that f(x+y)=f(x)+f(y) for all xa n dya n df(x)=(2x^2+3x)g(x) for all x , where g(x) is continuous and g(0)=3. Then find f^(prime)(x)dot

Let f(x)=|x| and g(x)=|x^3| , then (a). f(x) and g(x) both are continuous at x=0 (b) f(x) and g(x) both are differentiable at x=0 (c) f(x) is differentiable but g(x) is not differentiable at x=0 (d) f(x) and g(x) both are not differentiable at x=0

Let f(x+y)=f(x)+f(y) and f(x)=x^2g(x)AA x,y in R where g(x) is continuous then f'(x) is

Let f(x) be a function satisfying f(x+y)=f(x)+f(y) and f(x)=x g(x)"For all "x,y in R , where g(x) is continuous. Then,

Let g(x) be a polynomial of degree one and f(x) be defined by f(x)=-g(x), x 0 If f(x) is continuous satisfying f'(1)=f(-1) , then g(x) is