Çözüldü Area and Integration

What is the area of the region in the first quadrant bounded by the graph of y = e^(x / 2) and the line x = 2 ?

A) 2e - 2
B) 2e
C) e / 2 - 1
D) (e - 1) / 2
E) e - 1

https://secure-media.collegeboard.org/digitalServices/pdf/ap/ap-calculus-ab-practice-exam-2012.pdf
[Page 8 (26 in the pdf file), Answers: Page 74 in the pdf file]

x / 2 = u ⇒ dx = 2du, u1 = 0 / 2 = 0, u2 = 2 / 2 = 1
(lower bound u1 = 0, upper bound u2 = 1), ∫ (e^u)2du =
(lower bound u1 = 0, upper bound u2 = 1), 2∫ (e^u)du =
(lower bound u1 = 0, upper bound u2 = 1), 2|e^u| =
2(e^1 - e^0) =
2(e - 1) =
2e - 2.

Check by WolframAlpha: https://www.wolframalpha.com/input?i=area between y = e^(x / 2), y = 0, 0<=x<=2