Question

Difficulty: EasyDefinite Integrals and Area Under Curves

Evaluate the definite integral 02(3x2+4)dx\int_{0}^{2} (3x^2 + 4) \, dx.

Answer: 16

Answer

The value of the definite integral is 1616.
Integrating 3x2+43x^2 + 4 with respect to xx gives the antiderivative F(x)=x3+4xF(x) = x^3 + 4x. Evaluating this antiderivative at the upper limit x=2x = 2 yields 23+4(2)=162^3 + 4(2) = 16, and at the lower limit x=0x = 0 yields 03+4(0)=00^3 + 4(0) = 0. Subtracting the lower boundary value from the upper boundary value gives 160=1616 - 0 = 16.

Step-by-Step Solution

1
Integrate the polynomial term by term
\int (3x^2 + 4) dx = x^3 + 4x
Apply the power rule of integration \int x^n dx = \frac{x^{n+1}}{n+1} and \int k dx = kx.
2
Apply the fundamental theorem of calculus with limits 0 and 2
[x^3 + 4x]_0^2 = (2^3 + 4(2)) - (0^3 + 4(0)) = 16 - 0 = 16
Evaluate F(b) - F(a) where F(x) is the antiderivative.

Key Concept

Definite Integral Evaluation using the Fundamental Theorem of Calculus
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