Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
MHT CET202120 Sep 2021Evening ShiftMathematicsContinuity and DifferentiabilityActual

If f(x)= 4^ x- +4^ -x -2 (x- )^2 for , is continuous at x= , then = k for = k =

Options

  1. A2 2
  2. B( 2)^2
  3. C-4( 2)^2
  4. D8( 2)^2

Correct answer

C. -4( 2)^2

Step-by-step solution

f( )= _ x f(x)= _ x 4^ x- +4^ -4 -2 (x- )^2 Put x = + h . As x , h 0 aligned & f ( )= _ h 0 4^ h +4^ - h -1-1 ~h ^2 = _ h 0 (4^ h -1 ) h _ h 0 4^ - h -1 - h (-1) & =( 4)(- 4)=(2 2)(-2 2)=-4( 2)^2 aligned

Practice Continuity and Differentiability on Quantrex Academy →

More from Continuity and Differentiability

The function f(x) = |x| + |x - 1| is: 2026If f(x) = cases 1+x - 1-x x , & x 0 k, & x = 0 cases is continuous at x = 0 , then k = 2026The function y = ||x| - 1| is differentiable for all values of ' x ' except 2026Let f : R R be the function given by f(x) = |x - 2| + 3|x - 1| + ||x - 2| - 1| . What is the number of points where f is NOT differentiable? 2026For real numbers a and b , consider the function f : R R given by f(x) = cases -ax - b & if x 1. cases How many pairs (a, b) are there for which f is continuous at every point of R 2026If f(x) = cases ax + 7 & if x 1 cases is continuous at x = 1 , then 2026If the function f(x) defined by f(x) = cases ax + 1 & if x 3 bx + 3 & if x > 3 cases is continuous at x = 3 , then (a - b) = .......... 2026Let [x] denotes the greatest integer less than or equal to x and f(x) = [ ^2 x] , then which of the following is true ? 2026 Full Continuity and Differentiability list All MHT CET PYQs