Math Problem Statement

if y= x3 over cube root of x find the derivative. The answer would be 8 over 3 x and cube root of x squared ​

Solution

Let's find the derivative of the given function step by step:

Given:
y=x3x3y = \frac{x^3}{\sqrt[3]{x}}

First, express the cube root of xx as a power of xx. Recall that x3=x1/3\sqrt[3]{x} = x^{1/3}. So the function becomes:

y=x3x1/3y = \frac{x^3}{x^{1/3}}

Now, simplify the expression by subtracting exponents (since aman=amn\frac{a^m}{a^n} = a^{m-n}):

y=x313=x9313=x83y = x^{3 - \frac{1}{3}} = x^{\frac{9}{3} - \frac{1}{3}} = x^{\frac{8}{3}}

Now, differentiate with respect to xx using the power rule ddx[xn]=nxn1\frac{d}{dx}[x^n] = n x^{n-1}:

dydx=83x831=83x53\frac{dy}{dx} = \frac{8}{3} x^{\frac{8}{3} - 1} = \frac{8}{3} x^{\frac{5}{3}}

Thus, the derivative is:

dydx=83x53\frac{dy}{dx} = \frac{8}{3} x^{\frac{5}{3}}

So, the derivative of yy is 83x53\frac{8}{3} x^{\frac{5}{3}}.

This result differs from the expression you provided, which is 83xx23\frac{8}{3} x \sqrt[3]{x^2}. However, both forms are equivalent. The expression x53x^{\frac{5}{3}} is the same as xx23x \sqrt[3]{x^2}, because x53=xx23=xx23x^{\frac{5}{3}} = x \cdot x^{\frac{2}{3}} = x \sqrt[3]{x^2}.

Do you want more details or have any further questions on this? Here's a tip for you:

Tip: Always remember to simplify expressions before differentiating, especially when dealing with roots and powers.

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Math Problem Analysis

Mathematical Concepts

Differentiation
Exponents and Powers
Cube Root

Formulas

Power Rule for Derivatives: d/dx [x^n] = n x^(n-1)

Theorems

Power Rule

Suitable Grade Level

Grades 11-12