Question:
Consider the functions f(x) = x^2 and g(x) = 2x - 1.
(a) Find the points of intersection of the graphs of f(x) and g(x).
(b) Find the area of the region bounded by the graphs of f(x) and g(x) over the interval [0, 2].
Answer:
(a) To find the points of intersection, we need to set the two functions equal to each other and solve for x:
x^2 = 2x - 1
Rearranging the equation, we have:
x^2 - 2x + 1 = 0
Using factoring, we can rewrite the equation as:
(x - 1)(x - 1) = 0
This implies that x = 1 is the point of intersection of the two graphs.
(b) To find the area of the region bounded by the graphs of f(x) and g(x) over the interval [0, 2], we need to find the definite integral of the difference between the two functions over this interval:
Area = ∫[0, 2] (f(x) - g(x)) dx
= ∫[0, 2] (x^2 - (2x - 1)) dx
= ∫[0, 2] (x^2 - 2x + 1) dx
To integrate, we use the power rule:
∫ x^n dx = (1/(n+1)) * x^(n+1) + C
Applying the power rule to our integral:
= (1/3) * x^3 - x^2 + x | [0, 2]
Evaluating the integral and subtracting the lower limit from the upper limit:
= [(1/3) * (2^3) - 2^2 + 2] - [(1/3) * (0^3) - 0^2 + 0]
= [(8/3) - 4 + 2] - [0 - 0 + 0]
= (8/3) - 4 + 2
= 2/3
Therefore, the area of the region bounded by the graphs of f(x) and g(x) over the interval [0, 2] is 2/3 square units.