Evaluate Definite Integral of 3x^2 + 4x - 5 from 1 to 2

Published on April 21, 2026

Calculus

Learn how to solve definite integrals using the power rule and the Fundamental Theorem of Calculus. This example evaluates the integral of 3x^2 + 4x - 5 from x=1 to x=2.

Question

Answer

The problem asks us to evaluate the definite integral:
To evaluate this definite integral, we first find the antiderivative of the function .
Using the power rule for integration, which states that (where ), we integrate each term:
The antiderivative of is .
The antiderivative of is .
The antiderivative of is .
So, the indefinite integral is:
Now, we need to evaluate this antiderivative from the lower limit to the upper limit . We use the Fundamental Theorem of Calculus, which states that , where is the antiderivative of .
Let .
We need to calculate .
First, evaluate :
Next, evaluate :
Finally, subtract from :
The final answer is .

Theorems

• Power Rule for Integration

The power rule for integration states that for any real number , the integral of with respect to is given by , where is the constant of integration.

• Fundamental Theorem of Calculus (Part 2)

The second part of the Fundamental Theorem of Calculus states that if is an antiderivative of a continuous function on the interval , then the definite integral of from to is given by .