A) \[(-2,\infty )\]
B) \[(2,\infty )\]
C) \[\left( 2,\frac{7}{2} \right)\]
D) None of these
Correct Answer: A
Solution :
| Let \[{{2}^{-x}}=t\] | |
| \[\therefore t>0\] | ?? (i) |
| \[\therefore \,\,2{{t}^{2}}-7t<4\] | |
| \[\Rightarrow \frac{-1}{2}<t<4\] | ?? (ii) |
| From (i) & (ii) |
| \[0<t<4\] |
| \[0<{{2}^{-x}}<4\] |
| \[\Rightarrow -2<x<\infty \] |
| \[\Rightarrow x\in (-2,\infty )\] |
You need to login to perform this action.
You will be redirected in
3 sec
