Most Important Selected Qs for JEE AdvancedMathematicsContinuity and Differentiability
Let f( x )= array ll 1 | x | , & | x | 1 ax ^2+ b , & | x | 1 array . be continuous and differentiable everywhere. Then a and b are -
Options
- A- 1 2 , 3 2
- B1 2 ,- 3 2
- C1 2 , 3 2
- D3 2 , 3 2
Correct answer
A. - 1 2 , 3 2
Step-by-step solution
aligned & f(x)= cases - 1 x , & x -1 a x^2+b, & -1 x 1 1 x , & x 1 cases & f^ (1⁺ )= _ h 0 1 1+h -1 h = _ h 0 -h h(1+h) =-1 & f^ (1⁻ )= _ h 0 a(1+h)^2+b-1 h & = _ n 0 a+b-1+2 a h+h^2 h & a + b =1 function differentiable at x =1 & f^ (1⁻ )=2 a & f^ (1⁻ )= f ^ (1⁺ ) 2 a =-1 a =- 1 2 & a+b=1 b= 3 2 . aligned