Sunday, May 27, 2018

Calculus and Its Applications, Chapter 1, 1.5, Section 1.5, Problem 48

If $\displaystyle y = x^{-\frac{3}{4}} - 3x^{\frac{2}{3}} + x^{\frac{5}{4}} + \frac{2}{x^4}$, find $y'$

$
\begin{equation}
\begin{aligned}
y' &= \frac{d}{dx} \left( x^{-\frac{3}{4}} - 3x^{\frac{2}{3}} + x^{\frac{5}{4}} + \frac{2}{x^4} \right)\\
\\
&= \frac{d}{dx} \left( x^{-\frac{3}{4}} \right) - \frac{d}{dx} \left( 3x^{\frac{2}{3}}\right) + \frac{d}{dx} \left( x^{\frac{5}{4}} \right)+ \frac{d}{dx} \left( \frac{2}{x^4} \right)\\
\\
&= \frac{d}{dx} \left( x^{-\frac{3}{4}} \right) - 3 \cdot \frac{d}{dx} \left( x^{\frac{2}{3}} \right) + \frac{d}{dx} \left( x^{\frac{5}{4}} \right) +
2 \cdot \frac{d}{dx} \left( x^{-4} \right)\\
\\
&= -\frac{3}{4} \cdot x^{-\frac{3}{4}-1} - 3 \cdot \frac{2}{3} x^{\frac{2}{3} - 1} + \frac{5}{4} \cdot x^{\frac{5}{4}-1} + 2 \cdot (-4) x^{-4-1}\\
\\
&= -\frac{3}{4}x^{-\frac{7}{4}} - 2 x^{-\frac{1}{3}} + \frac{5}{4} x^{\frac{1}{4}} - 8x^{-5}\\
\\
&= \frac{-3}{4x^{\frac{7}{4}}} - \frac{2}{x^{\frac{1}{3}}} + \frac{5}{4} x^{\frac{1}{4}} - \frac{8}{x^5}

\end{aligned}
\end{equation}
$

No comments:

Post a Comment

Why is the fact that the Americans are helping the Russians important?

In the late author Tom Clancy’s first novel, The Hunt for Red October, the assistance rendered to the Russians by the United States is impor...