Is 9^x + 9^(-x) = b ?
(1)x > 0 = b
Is is a sufficient condition?
Here is my working:
putting value of b we get
Is 9^x + 9^(-x) = 0 ?
=> 9^x + 1/9^x = 0
=>( 9^2x + 1 ) /9^x = 0
This will be true only if 9^x (is not equal to) 0
and 9^2x = -1 (this is not possible as even power cannot be -ve)
and 9^x cannot be 0.
Hence this provides answer NO to the question and should be sufficeint.
(But the answer is NOT Sufficient)
Can someone please explain where i am going wrong ?
thanks.
(1)x > 0 = b
Is is a sufficient condition?
Here is my working:
putting value of b we get
Is 9^x + 9^(-x) = 0 ?
=> 9^x + 1/9^x = 0
=>( 9^2x + 1 ) /9^x = 0
This will be true only if 9^x (is not equal to) 0
and 9^2x = -1 (this is not possible as even power cannot be -ve)
and 9^x cannot be 0.
Hence this provides answer NO to the question and should be sufficeint.
(But the answer is NOT Sufficient)
Can someone please explain where i am going wrong ?
thanks.
