To find the value of ‘a’ such that the line x = a bisects the area under the curve y = 1/x² for the interval [1, 4], we need to follow a series of steps:
Step 1: Calculate the total area under the curve.
The area under the curve from x = 1 to x = 4 can be computed using the definite integral:
A = ∫14 (1/x²) dx
Calculating this integral:
A = [-1/x]14 = [-1/4 - (-1/1)] = 1 - 1/4 = 3/4
Step 2: Determine the area to be bisected.
Since we want to find the line x = a that bisects this area, we need half of the total area:
Area_{left} = Area_{right} = 3/4 ÷ 2 = 3/8
Step 3: Set up the equation for the area on the left side of the line.
The area under the curve from x = 1 to x = a using the same integral setup gives:
Area_{left} = ∫1a (1/x²) dx = [-1/x]1a = -1/a + 1
Step 4: Set the area equation equal to 3/8.
Now, we set the area from x = 1 to x = a equal to 3/8:
-1/a + 1 = 3/8
Step 5: Solve for ‘a’.
Rearranging and solving for a:
-1/a = 3/8 - 1 → -1/a = 3/8 - 8/8 = -5/8 → a = 8/5
Conclusion:
Thus, the value of a that bisects the area under the curve y = 1/x² from x = 1 to x = 4 is:
a = 8/5 = 1.6
Therefore, a = 1.6 is the point where the line x = a divides the area equally.