# Math Help - Finding derivatives

1. ## Finding derivatives

Guys, how do I differentiate

(a) x/7

and

(b) (1/4)(√x)

And finally, what is

Thank You!

2. as we know
d(x^n)/dx nx^(n-1)
and
d(ax)/dx = a d(x)/dx where a is a constant

therefor
d(x/7)/dx = (1/7) d(x)/dx=1/7 (as d(x)/dx=1)

you may try other one yourself.feel free to ask if you face any problem.

3. Originally Posted by nikhil
as we know
d(x^n)/dx nx^(n-1)
and
d(ax)/dx = a d(x)/dx where a is a constant

therefor
d(x/7)/dx = (1/7) d(x)/dx=1/7 (as d(x)/dx=1)

you may try other one yourself.feel free to ask if you face any problem.

Am I right in saying that

a) dy/dx = 1/7

and

b) dy/dx = 1 / 8√x

so my rate of substitution would be (1/7) / (1 / (8√x))/ Is there a way to simplify this further?

4. Originally Posted by Archimedes
Am I right in saying that

a) dy/dx = 1/7 Mr F says: Correct.

and

b) dy/dx = 1 / 8√x Mr F says: If you mean dy/dx = 1 /(8√x), then yes you're answer is correct.

so my rate of substitution would be (1/7) / (1 / (8√x))/ Is there a way to simplify this further? Mr F says: Yes. Note that (a/b) / (c/d) = (ad)/(bc) ...
..

5. well you got the differentiation correct
now
simply
(1/7)/(1/8(x)^(1/2))=(8(x)^(1/2))/7

6. Ok now Ive got (1 / (8√x)) / 7

Does that mean my final answer is (8√x)/7 ?

Edit: Nikhal confirmed in above post.

Thanks to both of you guys so much!

7. yes that's the final answer.