Thread: differentiation applying two rules

oh ! so is my answer incorrect ?

here is my second example - please see if my inital steps are correct- while I get my head around what I did wrong in first example- ta

what you mean?

Ok I read what you said and I tried again- you can't fail me for trying. Please have a look

Originally Posted by vidhi96

what you mean?

For that last example, you overlooked squaring the entire denominator.

What I meant earlier is that you are comfortable with the situation
where the "function nesting" is one level deep, when applying the chain rule.

is one level beyond

q=6x



However...



has an extra stage.

Beginning with x, we have



but then we take the square root of this



so the "nesting" is 2 levels deep, whereas it was only 1 level deep for

Hence





How is that ?

Originally Posted by vidhi96

Ok I read what you said and I tried again- you can't fail me for trying. Please have a look

On your line beginning "Therefore", you do not have the correct derivative for "v",
but you corrected yourself on the final line!

Originally Posted by Prove It

Now apply the chain rule to find these derivatives.

Hey following some discussion with someone else and you- I have done some work- do you mind seeing what I have done is correct so I know I am ok to work with product and quotient rule both

so you are telling me I am finally right

Originally Posted by Archie Meade

On your line beginning "Therefore", you do not have the correct derivative for "v",
but you corrected yourself on the final line!

I take it I finally understand how it works- Please say yes!!! I have also completed my own second eaxmple - heres my final version please look at it - I am typing so i can send it-therefore please excaue miner mistakes but please point to it

Originally Posted by vidhi96

so you are telling me I am finally right

Yes, but do look at why you wrote the derivative of "v" incorrectly,
before plugging the correct derivative of v into the Product Rule formula.
For your Quotient Rule example, you still have not squared the denominator.

Originally Posted by Archie Meade

Yes, but do look at why you wrote the derivative of "v" incorrectly,
before plugging the correct derivative of v into the Product Rule formula.
For your Quotient Rule example, you still have not squared the denominator.

Ok I will do squaring and see if I can simplify in any way. However I take it rest of is ok. Is that correct? Also I know why I made mistake in "v" because I wasn't careful but since you pointed it out I think I will be extra carful in writing my steps out. Just away from the computer for next hour so when get back will send you my correction. I must say you have given me that confidence I thought I'll never have . Sincere thank you