Most Important Selected Qs for JEE AdvancedMathematicsFunctions
f: R R is defined as f(x)= [ array ll x^2+2 m x-1 & for x 0 m x-1 & for x 0 array . . If f(x) is one-one then m must lies in the interval
Options
- A(- , 0)
- B(- , 0]
- C(0, )
- D[0, )
Correct answer
A. (- , 0)
Step-by-step solution
for f^2 to be one-one f^ (x) 0 and f^ (x) 0 for all x clearly f is continuous at x=0 and f(0)=-1x 0, f^ (x)=2(x+m) for x 0f^ (x) can not be 0 for x 0 if m 0 f ^ ( x ) 0 for m 0 but m 0 as for x 0, f is constant and m 0, f ^ ( x ) 0, x 0