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Math Snap
PROBLEM
22. Consider f(x)=x2−3x+3 and g(x)=x. (1) Find the points of intersection, (2) Find the area of the region between two curves.
STEP 1
Assumptions 1. The function f(x)=x2−3x+3 represents a parabola. 2. The function g(x)=x represents a straight line. 3. We need to find the points of intersection of these two functions. 4. We need to calculate the area of the region between the two curves over the interval defined by their points of intersection.
STEP 2
To find the points of intersection, set f(x)=g(x). x2−3x+3=x
STEP 3
Rearrange the equation to form a quadratic equation. x2−3x+3−x=0x2−4x+3=0
STEP 4
Solve the quadratic equation x2−4x+3=0 using the quadratic formula: x=2a−b±b2−4acwhere a=1, b=−4, and c=3.
STEP 5
Calculate the discriminant b2−4ac. (−4)2−4×1×3=16−12=4
STEP 6
Substitute the values into the quadratic formula. x=2×1−(−4)±4x=24±2
STEP 7
Calculate the two possible solutions for x. x1=24+2=3x2=24−2=1
STEP 8
The points of intersection are when x=1 and x=3. Find the corresponding y-values using g(x)=x. For x=1, y=1. For x=3, y=3. Thus, the points of intersection are (1,1) and (3,3).
STEP 9
To find the area between the curves, integrate the difference f(x)−g(x) from x=1 to x=3. Area=∫13(f(x)−g(x))dxArea=∫13(x2−3x+3−x)dxArea=∫13(x2−4x+3)dx
STEP 10
Integrate the function x2−4x+3. ∫(x2−4x+3)dx=3x3−2x2+3x+C
STEP 11
Evaluate the definite integral from x=1 to x=3. [3x3−2x2+3x]13
STEP 12
Calculate the value at x=3. 333−2(3)2+3(3)=327−18+9=9−18+9=0
STEP 13
Calculate the value at x=1. 313−2(1)2+3(1)=31−2+3=31+1=34
STEP 14
Subtract the result at x=1 from the result at x=3. 0−34=−34
SOLUTION
Since the area cannot be negative, take the absolute value. Area=34The area of the region between the two curves is 34 square units.