If (x)2 = [x]2 + 2x then which of the following is true. Where [x] represents greatest integer less than or equal to x. (x) represents integer just greater than or equal to x. I represents Integer.
If (x)2 = [x]2 + 2x then which of the following is true. Where [x] represents greatest integer less than or equal to x. (x) represents integer just greater than or equal to x. I represents Integer. Correct Answer <span class="fontstyle2">x = n + 1/2, n </span><span style="color: rgb(32, 33, 36);">∈</span><span class="fontstyle2"> I or </span>x = 0
Calculation:
Case I:
⇒ Let x = n ∈ I
⇒ Given equation becomes:
⇒ n2 = n2 + 2n
⇒ n = 0
Case II:
⇒ Let x ∈ I
⇒ i.e. n < x < n + 1
⇒ Given equation becomes:
⇒ (n - 1)2 = n2 + 2x
⇒ x = n + 1/2, n ∈ I
⇒ Therefore x = 0 or x = n + 1/2; n ∈ I
+ {x}; where {x} represent fraction part of x.
⇒ x = (x) - (1 - {x})
⇒ (x + 1 - {x})2 = (x - {x})2 + 2x (Using given equation)
⇒ (x + 1 - {x})2 + 1 + 2 (x - {x})2 = (x - {x})2 + 2x
⇒ 1 - 2 {x} = 0
⇒ {x} = 1/2
⇒ x = n + 1/2, n ∈ I
⇒ Also, x = 0, by observation.