25 multiple choice 1 point the length of the curve y = x^4 from x = 1 to x = 5 is given by (a) ∫₁⁵√(1 + 4x³)…

25 multiple choice 1 point the length of the curve y = x^4 from x = 1 to x = 5 is given by (a) ∫₁⁵√(1 + 4x³) dx (b) ∫₁⁵√(1 + x⁴) dx (c) ∫₁⁵√(1 + 4x⁶) dx (d) ∫₁⁵√(1 + 16x⁶) dx (e) ∫₁⁵√(1 + x⁸) dx a b c d e previous
Answer
Answer:
C. $\int_{1}^{5}\sqrt{1 + 4x^{6}}dx$
Explanation:
Step1: Recall arc - length formula
The arc - length formula for a curve $y = f(x)$ from $x=a$ to $x = b$ is $L=\int_{a}^{b}\sqrt{1+(y')^{2}}dx$.
Step2: Differentiate $y = x^{4}$
If $y=x^{4}$, then by the power rule $(x^{n})'=nx^{n - 1}$, we have $y' = 4x^{3}$.
Step3: Calculate $(y')^{2}$
$(y')^{2}=(4x^{3})^{2}=16x^{6}$.
Step4: Substitute into arc - length formula
Substitute $(y')^{2}=16x^{6}$ into $L=\int_{a}^{b}\sqrt{1+(y')^{2}}dx$ with $a = 1$, $b = 5$. We get $L=\int_{1}^{5}\sqrt{1 + 16x^{6}}dx$.