f(x)=x raise to 2( x square)-3x+1,find k if f(2k)=2f(k) and f(2k)=f(k).
Asked by pooja dev | 20th Nov, 2010, 12:00: AM
Dear Student,
f (x) = x2 -3x +1
=> f (2k) = (2k)2 - 3(2k) + 1
=> f (2k) = 4k2 - 6k + 1
And f (k) = k2 -3k +1
As, f (2k) = 2f (k)
=> 4k2 - 6k + 1 = 2k2 -6k +2
=> 2k2 -1 = 0
=> k2 = 1/2
=> k = 1/√2 or -1/√2
And for f (2k) = f (k)
i.e. 4k2 - 6k + 1 = k2 -3k +1
=> 3k2 - 3k = 0
=> 3k (k-1) = 0
=> k = 0 or 1.
Regards Topperlearning.
Dear Student,
f (x) = x2 -3x +1
=> f (2k) = (2k)2 - 3(2k) + 1
=> f (2k) = 4k2 - 6k + 1
And f (k) = k2 -3k +1
As, f (2k) = 2f (k)
=> 4k2 - 6k + 1 = 2k2 -6k +2
=> 2k2 -1 = 0
=> k2 = 1/2
=> k = 1/√2 or -1/√2
And for f (2k) = f (k)
i.e. 4k2 - 6k + 1 = k2 -3k +1
=> 3k2 - 3k = 0
=> 3k (k-1) = 0
=> k = 0 or 1.
Regards Topperlearning.
Answered by | 21st Nov, 2010, 12:14: PM
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