Q. The value of ∫131+x2dx is:(a) 2π(b) 32π(c) 6π(d) 12π
Recognize standard form: Recognize the integral as a standard form. The integral of 1+x21 is a standard form that is recognized as the inverse tangent function, arctan(x). Therefore, the integral can be written as: ∫1+x2dx=arctan(x)+C
Apply limits of integration: Apply the limits of integration. We need to evaluate the definite integral from 1 to 3, which means we will substitute these values into the antiderivative we found in Step 1: ∫131+x2dx=arctan(3)−arctan(1)
Evaluate arctan function: Evaluate the arctan function at the limits. arctan(3) corresponds to the angle whose tangent is 3, which is 3π because tan(3π)=3.arctan(1) corresponds to the angle whose tangent is 1, which is 4π because tan(4π)=1.
Perform subtraction: Perform the subtraction to find the exact value.Now we subtract the two values:arctan(3)−arctan(1)=(3π)−(4π)
Simplify expression: Simplify the expression.To subtract the fractions, find a common denominator, which is 12 in this case:(π/3)−(π/4)=(4π/12)−(3π/12)=(π/12)
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