how to find dw/dx of w= x+4
Just take the derivative with respect to x,
HOw?
the answer is 1 but i cant understand how?
\[w=x+4\]\[\frac{dw}{dx} = \frac{dx}{dx}+\frac{d4}{dx}\]This is just like taking the derivative. Have you learned how to take derivatives?
no
Because w is a FUNCTION of x, when we're taking the derivative of a variable with respect to another variable, we label that as a prime, \(w'\). If we're taking the derivative of a variable with respect to itself, it depends upon the power rule of the variable. in this case, \(\frac{d}{dx}(x^1) = 1\)
These are just rules in your Calculus book you have to follow. http://www.mathsisfun.com/calculus/derivatives-introduction.html use this for more information about finding derivatives.
@Ghayyas.mubashir Do you know the definition of a derivative?
Have you seen this: \[ \frac{df}{dx} = \lim_{h\to 0}\frac{f(x+h)-f(x)}{h} \]
yeh but i cant understand that
Okay, let's start from the basics then...
yes plzz
\[ w = f(x) = x+4 \]Do you understand this?
yeh
Okay, now: \[ f(\color{red}{x+h}) = (\color{red}{x+h})+4 \]Does this make sense?
We substituted in \(x+h\) for \(x\).
yeh
Now we plug these into the limit. \[ \lim_{h\to 0}\frac{f(x+h)-f(x)}{h}=\lim_{h\to 0}\frac{(x+h+4)-(x+4)}{h} \]
Do you understand the substitutions I did here?
yes
Can you simplify: \[ \lim_{h\to 0}\frac{(x+h+4)-(x+4)}{h} \]?
wait a min i try
i cant
\[ \lim_{h\to 0}\frac{(x+h+4)-(x+4)}{h} = \lim_{h\to 0}\frac{x+h+4-x-4}{h} =\lim_{h\to 0}\frac{h}{h}=\lim_{h\to0}1=1 \]?
\[ \frac{dw}{dx}=\frac{df}{dx}=1 \]
May god help you if you ever are tested on this.
h/h =0 then y is equal to 1?
???
You make me sad.
soory but plz if u can
\[ \frac 44 = ? \]
1
\[ \frac hh = ? \]
but h = 0
0/0 ? = 1?
No, that isn't how limits work.
any number that has limit 0 it would be always one??
When you are doing a limit, like \[ \lim_{x\to a}f(x) \]Then you assume that \(x\) is very close to \(a\), but that \(x\neq a\).
hey ghayyas
You should really use the link I provided you in the posts above to learn about limits and derivatives to get a general idea of how they work.
you are learning first principle?
first principle is basically comes from the equation of a line
hi dan815 abd thank you much jhanny bean and best regards wio
dian i understand now. thank you so much
okay
np
a big thans to wio who help me alot.. Thank you SOOOOO MUCH,,
You're welcome. "First principle" Where does that even come from?
Is there a second principle?
what is first principle>?
Yeah that's what i'm wondering.
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