Question
What is the area of the region enclosed by the graphs of $y=e^x-2$, $y=\sin x$, and $x=0$ ?
Original question: What is the area of the region enclosed by the graphs of , , and ?
A 0.239 B 0.506 C 0.745 D 2.340 E 3.472
Expert Verified Solution
thumb_up100%(1 rated)
Key concept: To find the enclosed area, identify the intersection point of the two curves and integrate the top function minus the bottom function.
Step by step
We want the area enclosed by
Step 1: Find the intersection point
The curves meet where
This equation has a solution between and . Let that intersection be at .
Step 2: Determine which curve is on top
For between and , the sine curve is above the exponential curve, so the area is
That is
Step 3: Integrate
So
= -\cos a-e^a+2a+2.$$ Using the intersection value numerically gives $$A\approx 0.745.$$ Therefore, the area is $$\boxed{0.745}$$ which is choice **C**. ### Pitfall alert A common mistake is to integrate from $0$ to a guessed endpoint without first locating the intersection of the two curves. Another error is reversing top and bottom, which would make the area negative before taking the absolute value. ### Try different conditions If the vertical line $x=0$ were replaced by another boundary such as $x=c$, then the limits of integration would change accordingly. The same method still applies: find where the curves intersect and subtract bottom from top over the bounded interval. ### Further reading area between curves, intersection point, definite integralFAQ
How do you set up the area integral?
Find the intersection of y=e^x-2 and y=sin x, then integrate the top curve minus the bottom curve from x=0 to the intersection point.
What is the area of the region?
The area is approximately 0.745 square units.