Question:
Let f(x)=x2−3x and g(x)=2x−1 be two functions defined for 0≤x≤4. Find the area of the region bounded by the curves f(x) and g(x).
Answer:
To find the area of the region bounded by the curves f(x) and g(x), we need to determine the points of intersection between the two curves first.
Setting f(x)=g(x), we have:
x2−3x=2x−1
Simplifying the equation, we get:
x2−5x+1=0
We can solve this quadratic equation by factoring or using the quadratic formula. However, upon inspection, we can see that there are no real solutions for this equation. Thus, the curves f(x) and g(x) do not intersect in the given interval 0≤x≤4.
Therefore, the area bounded by the curves is equal to the area under f(x) minus the area under g(x).
Let's first find the area under f(x):
Af=∫04f(x)dx
Af=∫04(x2−3x)dx
Using the power rule of integration, we can integrate term by term:
Af=[31x3−23x2]04Af=(31⋅43−23⋅42)−(31⋅03−23⋅02)Af=(31⋅64−23⋅16)−(0−0)Af=364−248Af=364−24Af=364−372Af=−38Next, let's find the area under g(x):
Ag=∫04g(x)dx
Ag=∫04(2x−1)dx
Again, we can integrate term by term:
Ag=[x2−x]04Ag=(42−4)−(02−0)Ag=(16−4)−(0−0)Now, we can find the area bounded by the curves:
Area=Af−Ag
Area=−38−12
Area=−38−336
Area=−344
Therefore, the area of the region bounded by the curves f(x) and g(x) is −344 square units.