Let the area bounded by the equation : and the -axis be
Find the positive integer satisfying
Submit
Notation: denotes the Riemann Zeta function .
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
lo g ( y ) + lo g 2 ( x ) = 1 ⟹ y = e 1 − lo g 2 ( x )
y = 0 when it touches x axis . So there are two limits x → ∞ and x → 0
Area = ∫ 0 ∞ e 1 − lo g 2 ( x ) d x Take lo g ( x ) = t , the integral becomes= e ∫ − ∞ ∞ e t − t 2 d t = e ∫ − ∞ ∞ e − ( t − 2 1 ) 2 + 4 1 d t = e 4 5 ∫ − ∞ ∞ e − ( t − 2 1 ) 2 d t = e 4 5 π (Gaussian Integral) So A = e 4 5 π and A 4 = e 5 π 2 = ( 2 2 + 2 ) e 2 2 + 1 6 π 2
So A 4 = ( 2 2 + 2 ) e 2 2 + 1 ζ ( 2 ) - Answer b = 2