# Quick calc question for Dy/Dx

1. May 7, 2004

### Spectre32

Ok i have an easy function:

1/(5x^7sqrt(x)) Now i am asked to derive this. What would be the best method. I thought about the quotent rule, and i'm thinkin thats my best bet. Also, does anyone know if there is a program out there that shows steps to Derivaties and Intergration. I have my final comming up and i want to know if i'm doing all of my review problems correctly.

2. May 7, 2004

### cookiemonster

Do you mean

$$\frac{1}{5x^7\sqrt{x}}$$

If so, this can be written as

$$\frac{1}{5}x^{-15/2}$$

and differentiated using the power rule.

cookiemonster

3. May 7, 2004

### Spectre32

ahhh whoops, i forgot about that, Thanks for the help.

4. May 8, 2004

### Gokul43201

Staff Emeritus
Your description of the function is not clear. Is the sqrt(x) also in the exponent ?

If you mean y = 1/[5*x^{7*sqrt(x)}], it's a little harder. Then you take the logarithm on both sides - which converts the exponent into a product - before differentiating.

That way, the answer would be y' = [-7/{sqrt(x)*x^(7*sqrt(x))}]*[1 - (1/2)*log(x)]

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