The value of the definite integral above is equal to where , , , and are positive integers. Find the value of
Bonus: Find the general form of the indefinite integral for positive integers .
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.
I = ∫ x n − x d x = ∫ x ( x n − 1 − 1 ) d x = ∫ ( x n − 1 − 1 x n − 2 − x 1 ) d x = n − 1 ln ( x n − 1 − 1 ) − ln x + C where C is the constant of integration.
Therefore,
∫ e ∞ x 2 0 1 7 − x d x = 2 0 1 6 ln ( x 2 0 1 6 − 1 ) − ln x ∣ ∣ ∣ ∣ e ∞ = x → ∞ lim ln ( x 2 0 1 6 x 2 0 1 6 − 1 ) 2 0 1 6 1 − 2 0 1 6 ln ( e 2 0 1 6 − 1 ) + ln e = x → ∞ lim ln ( 1 − x 2 0 1 6 1 ) 2 0 1 6 1 − 2 0 1 6 ln ( e 2 0 1 6 − 1 ) + 1 = 0 + 1 − 2 0 1 6 ln ( e 2 0 1 6 − 1 )
⟹ a + b + c + d = 1 + 2 0 1 6 + 2 0 1 6 + 1 = 4 0 3 4 .