Solve 3/x*x^3/12

$$\frac { 3 } { x } \cdot \frac { x ^ { 3 } } { 12 }$$

Evaluate

$$\frac{x^{2}}{4}$$

Solution Steps

Multiply \frac{3}{x} times \frac{x^{3}}{12} by multiplying numerator times numerator and denominator times denominator.

$$\frac{3x^{3}}{x\times 12}$$

Cancel out 3x in both numerator and denominator.

$$\frac{x^{2}}{4}$$

Differentiate w.r.t. x

$$\frac{x}{2}$$

Steps Using Derivative Rule for Product

For any two differentiable functions, the derivative of the product of two functions is the first function times the derivative of the second plus the second function times the derivative of the first.

$$3\times \frac{1}{x}\frac{\mathrm{d}}{\mathrm{d}x}(\frac{1}{12}x^{3})+\frac{1}{12}x^{3}\frac{\mathrm{d}}{\mathrm{d}x}(3\times \frac{1}{x})$$

The derivative of a polynomial is the sum of the derivatives of its terms. The derivative of a constant term is 0. The derivative of ax^{n} is nax^{n-1}.

$$3\times \frac{1}{x}\times 3\times \frac{1}{12}x^{3-1}+\frac{1}{12}x^{3}\left(-1\right)\times 3x^{-1-1}$$

Simplify.

$$3\times \frac{1}{x}\times \frac{1}{4}x^{2}+\frac{1}{12}x^{3}\left(-3\right)x^{-2}$$

To multiply powers of the same base, add their exponents.

$$\frac{1}{4}\times 3x^{-1+2}+\frac{1}{12}\left(-3\right)x^{3-2}$$

Simplify.

$$\frac{3}{4}x^{1}-\frac{1}{4}x^{1}$$

For any term t, t^{1}=t.

$$\frac{3}{4}x-\frac{1}{4}x$$