Most Important Selected Qs for JEE AdvancedMathematicsContinuity and Differentiability
Let f(x)=x^3-x^2+x+1 and g(x)= array ll . f(t) ; 0 t x, & for 0 x 1 3-x, & for 1 < x 2 array . , then g(x) is:
Options
- Acontinuous for x [0,2]- 1
- Bcontinuous for x [0,2]
- Cderivable for all x [0,2]
- Dderivable for all x [0,2]- 1
Correct answer
D. derivable for all x [0,2]- 1
Step-by-step solution
f(x)=x^3-x^2+x+1 f^ (x)=3 x^2-2 x+1>0, f is increasing. g(x)= array cc f(x)=x^3-x^2+x+1, & 0 x 1 3-x, & 1 x 2 array . Clearly g(x) is continuous for all x [0,2] and g^ (x)= array cc 3 x^3-2 x+1, & 0 < x < 1 -1, & 1 < x < 2 array . g^ (1⁻ )=2 and g^ (1⁺ )=-1 g is non-derivable at x=1