Bytelearn - cat image with glassesAI tutor

Welcome to Bytelearn!

Let’s check out your problem:

Evaluate the integral and express your answer in simplest form.

int(1)/(xsqrt(x^(2)-25))dx
Answer:

Evaluate the integral and express your answer in simplest form.\newline1xx225dx \int \frac{1}{x \sqrt{x^{2}-25}} d x \newlineAnswer:

Full solution

Q. Evaluate the integral and express your answer in simplest form.\newline1xx225dx \int \frac{1}{x \sqrt{x^{2}-25}} d x \newlineAnswer:
  1. Recognize standard inverse trigonometric form: Recognize the integral as a standard inverse trigonometric form.\newlineThe integral 1xx225dx\int\frac{1}{x\sqrt{x^2-25}}dx can be recognized as an inverse trigonometric integral because the denominator has the form of a2u2a^2 - u^2, where a=5a = 5 and u=xu = x. This suggests a substitution using the inverse trigonometric function secant.
  2. Perform substitution with secant: Perform the substitution x=5sec(θ)x = 5\sec(\theta). Let x=5sec(θ)x = 5\sec(\theta), which implies dx=5sec(θ)tan(θ)dθdx = 5\sec(\theta)\tan(\theta)d\theta. We also need to express x225\sqrt{x^2-25} in terms of θ\theta. Since x=5sec(θ)x = 5\sec(\theta), we have x225=25sec2(θ)25=25(tan2(θ))=5tan(θ)\sqrt{x^2-25} = \sqrt{25\sec^2(\theta)-25} = \sqrt{25(\tan^2(\theta))} = 5\tan(\theta).
  3. Rewrite integral in terms of theta: Rewrite the integral in terms of θ\theta. Substituting xx and dxdx into the integral, we get 15sec(θ)5tan(θ)5sec(θ)tan(θ)dθ\int\frac{1}{5\sec(\theta)\cdot 5\tan(\theta)} \cdot 5\sec(\theta)\tan(\theta)d\theta. The 55's and sec(θ)tan(θ)\sec(\theta)\tan(\theta) cancel out, leaving us with 15tan(θ)5sec(θ)tan(θ)dθ=dθ\int\frac{1}{5\tan(\theta)} \cdot 5\sec(\theta)\tan(\theta)d\theta = \int d\theta.
  4. Integrate with respect to theta: Integrate with respect to θ\theta. The integral of dθd\theta is simply θ\theta. So we have dθ=θ+C\int d\theta = \theta + C, where CC is the constant of integration.
  5. Back-substitute for x: Back-substitute to express the answer in terms of x.\newlineWe originally let x=5sec(θ)x = 5\sec(\theta), so we need to solve for θ\theta in terms of xx. We have sec(θ)=x5\sec(\theta) = \frac{x}{5}, and taking the inverse secant of both sides gives us θ=sec1(x5)\theta = \sec^{-1}(\frac{x}{5}). Therefore, the integral in terms of xx is sec1(x5)+C\sec^{-1}(\frac{x}{5}) + C.