Bytelearn - cat image with glassesAI tutor

Welcome to Bytelearn!

Let’s check out your problem:

Find the limit as 
x approaches negative infinity.

lim_(x rarr-oo)(sqrt(x^(8)-5x^(3)))/(3x^(4)+4)=

Find the limit as x x approaches negative infinity.\newlinelimxx85x33x4+4= \lim _{x \rightarrow-\infty} \frac{\sqrt{x^{8}-5 x^{3}}}{3 x^{4}+4}=

Full solution

Q. Find the limit as x x approaches negative infinity.\newlinelimxx85x33x4+4= \lim _{x \rightarrow-\infty} \frac{\sqrt{x^{8}-5 x^{3}}}{3 x^{4}+4}=
  1. Identify highest power: Identify the highest power of xx in both the numerator and the denominator to simplify the limit expression.\newlineIn the numerator, the highest power of xx is x8x^8 inside the square root, which is equivalent to x4x^4 when taken outside the square root. In the denominator, the highest power of xx is x4x^4.
  2. Divide by x4x^4: Divide both the numerator and the denominator by x4x^4, the highest power of xx in the denominator.\newlinelimx(x85x3)/(3x4+4)=limx((x8/x4)(5x3/x4))/((3x4/x4)+(4/x4))\lim_{x \to -\infty}(\sqrt{x^{8}-5x^{3}})/(3x^{4}+4) = \lim_{x \to -\infty}(\sqrt{(x^{8}/x^{4})-(5x^{3}/x^{4})})/((3x^{4}/x^{4})+(4/x^{4}))
  3. Simplify expression: Simplify the expression inside the limit by canceling out the powers of xx.\[\lim_{x \to -\infty}\left(\frac{\sqrt{\left(\frac{x^{\(8\)}}{x^{\(4\)}}\right)-\left(\frac{\(5\)x^{\(3\)}}{x^{\(4\)}}\right)}}{\left(\frac{\(3\)x^{\(4\)}}{x^{\(4\)}}\right)+\left(\frac{\(4\)}{x^{\(4\)}}\right)}\right) = \lim_{x \to -\infty}\left(\frac{\sqrt{x^{\(4\)}-\frac{\(5\)}{x}}}{\(3\)+\frac{\(4\)}{x^{\(4\)}}}\right)
  4. Approach negative infinity: As \(x\) approaches negative infinity, the terms \(-\frac{5}{x}\) and \(\frac{4}{x^{4}}\) approach \(0\).\(\lim_{x \rightarrow -\infty}\left(\frac{\sqrt{x^{4}-\frac{5}{x}}}{3+\frac{4}{x^{4}}}\right) = \lim_{x \rightarrow -\infty}\left(\frac{\sqrt{x^{4}}}{3}\right)\)
  5. Evaluate square root: Evaluate the square root of \(x^4\) as \(x\) approaches negative infinity.\(\newline\)Since \(x\) is approaching negative infinity, we must consider that the square root of \(x^4\) is the absolute value of \(x^2\), which is \(|x^2|\). However, since \(x\) is negative, \(|x^2| = x^2\) because the square of a negative number is positive.\(\newline\)\(\lim_{x \to -\infty}(\sqrt{x^{4}})/3 = \lim_{x \to -\infty}(x^2)/3\)
  6. Determine limit: Determine the limit of \(x^2/3\) as \(x\) approaches negative infinity.\(\newline\)As \(x\) approaches negative infinity, \(x^2\) approaches positive infinity. Therefore, the limit of \(x^2/3\) as \(x\) approaches negative infinity is positive infinity.\(\newline\)\(\lim_{x \to -\infty}(x^2)/3 = +\infty\)