How do you integrate (r^2-x^2)^(1/2) with a constant r?

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In summary, the formula for integrating (r^2-x^2)^(1/2) is ∫(r^2-x^2)^(1/2)dx = (x/2)*(√(r^2-x^2) + r^2*sin^(-1)(x/r)) + C, where C is the constant of integration. The domain of integration for (r^2-x^2)^(1/2) is [-r, r] as the square root term becomes imaginary for values of x outside of this range. (r^2-x^2)^(1/2) can be solved using the substitution u = √(r^2-x^2), which transforms
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FUNKER
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how would you integrate
(r^2-x^2)^(1/2)
where r is constant
thanks peace
 
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  • #2
i think it's pretty straightforward with trig substitution. try replacing x with cos(u), sin(u) or tan(u) or something like that & the solution should drop out.
 
  • #3


To integrate (r^2-x^2)^(1/2), we can use the substitution method. Let u = r^2-x^2, then du = -2x dx. We can rewrite the integral as:

∫(r^2-x^2)^(1/2) dx = -1/2∫(r^2-x^2)^(-1/2) (-2x) dx

= -1/2∫u^(-1/2)du

= -1/2 * 2u^(1/2) + C

= -u^(1/2) + C

= -(r^2-x^2)^(1/2) + C

Therefore, the final answer is -(r^2-x^2)^(1/2) + C. I hope this helps! Peace.
 

1. What is the formula for integrating (r^2-x^2)^(1/2)?

The formula for integrating (r^2-x^2)^(1/2) is ∫(r^2-x^2)^(1/2)dx = (x/2)*(√(r^2-x^2) + r^2*sin^(-1)(x/r)) + C, where C is the constant of integration.

2. What is the domain of integration for (r^2-x^2)^(1/2)?

The domain of integration for (r^2-x^2)^(1/2) is [-r, r] as the square root term becomes imaginary for values of x outside of this range.

3. Can the integration of (r^2-x^2)^(1/2) be solved using substitution?

Yes, (r^2-x^2)^(1/2) can be solved using the substitution u = √(r^2-x^2), which transforms the integral into ∫u^2*(1-u^2/r^2) dx. This can then be solved by using the trigonometric substitution u = r*sin(θ) and applying the Pythagorean identity.

4. What is the physical significance of integrating (r^2-x^2)^(1/2)?

The integration of (r^2-x^2)^(1/2) can represent the area under a semicircle with radius r, where r is the distance from the center of the circle to the x-axis. This can be useful in calculating the area of a curved surface or in problems involving circular motion.

5. Can the integration of (r^2-x^2)^(1/2) be solved using integration by parts?

Yes, the integration of (r^2-x^2)^(1/2) can also be solved using integration by parts, by setting u = (r^2-x^2)^(1/2) and dv = dx. This method may be useful in certain cases where substitution is not applicable or more complicated.

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