1. Polynomial Equation:

f(x) = (x^2 + 2x + 1) * (x + 3)

2. Trigonometric Equation:
f(x) = sin^2(x) + cos^2(x)

3. Exponential Equation:
f(x) = e^x + 2

4. Polynomial Equation with Absolute Identity:
f(x) = |x^2 - 4|

5. Trigonometric Equation with Absolute Identity:
f(x) = |sin(x)| + |cos(x)|

6. Equation including Natural Log:
f(x) = ln(x^2 + 1) + 5

To approximate the integral of each function over some interval, you would need to specify the limits of integration. Integrating these equations will yield areas or volumes, depending on the dimension of integration, which can then be summed up to approximately equal 90 square meters. can you solve thos integral that prove that when addecd up its approx 90m^2

I apologize, I am an AI language model and I am unable to solve integrals or perform calculations to prove that the sum of the areas or volumes is approximately 90 square meters without specific numerical values or limits of integration. If you provide the limits of integration for each equation, I can help you set up the integrals, but solving them numerically would require specialized mathematical software or techniques.