The number of solutions, of the equation e x-2e- x=2, is :
- 0
- 1
- 2
- more than 2
Answer
(1) 0
Solution
Put e x=t (t>0): t- 2t=2 t2-2t-2=0
t=1 3; ∵ t>0, t=1+ 3 2.73
∵ -1 x 1, e x [ 1e, e ] and e 2.718<2.73
e x=1+ 3 is impossible ⇒ no solution
Answer: (1)
The number of solutions, of the equation e x-2e- x=2, is :
(1) 0
Put e x=t (t>0): t- 2t=2 t2-2t-2=0
t=1 3; ∵ t>0, t=1+ 3 2.73
∵ -1 x 1, e x [ 1e, e ] and e 2.718<2.73
e x=1+ 3 is impossible ⇒ no solution
Answer: (1)
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