AP EAMCET2006MathematicsContinuity and Differentiability
If f(x)= cases 1- 2 x -4 x & if x 4 a & if x= 4 cases is continuous at 4 , then a is equal to
Options
- A4
- B2
- C1
- D1 / 4
Correct answer
D. 1 / 4
Step-by-step solution
f(x)= cases 1- 2 x -4 x , & if x 4 a, & if x= 4 cases _ x 4 f(x)= _ x 4 1- 2 x -4 x = _ x 4 - 2 x -4 (By L' Hospital's rule) = 2 1 2 4 = 1 4 Since f(x) is continuous at x= 4 . _ x 4 f(x)=f ( 4 ) 1 4 =a