# differentiation using first priciple

#### Mathkid12

##### New member
Can anyone explain differentiation using first principle please....................

this is a question that i have no understanding on how to deal with it
IF y=x^2 + 2 show that dy/dx using first principle equals to 2x

#### Fernando Revilla

##### Well-known member
MHB Math Helper
$f'(x)=\displaystyle\lim_{h \to 0} \dfrac{f(x+h)-f(x)}{h}=\displaystyle\lim_{h \to 0} \dfrac{(x+h)^2+2-(x^2+2)}{h}=\ldots$

#### Mathkid12

##### New member
thanks can you please relate it to the question that i provided please, and thanks in advance

#### Fernando Revilla

##### Well-known member
MHB Math Helper
thanks can you please relate it to the question that i provided please, and thanks in advance
I interpretate using first principle as equivalent to using the definition. Am I wrong?

#### Mathkid12

##### New member
well i really dont know because I PRESENTLY DONT KNOW ANYTHING ABOUT Differentiation using first principle but thanks anywhere

MHB Math Helper

#### Mr Fantastic

##### Member
well i really dont know because I PRESENTLY DONT KNOW ANYTHING ABOUT Differentiation using first principle but thanks anywhere
Fernando Revilla has given you the first two steps. The next step should be clear: Expand the numerator and simplify. Then ....

If you really "DONT KNOW ANYTHING ABOUT Differentiation using first principle" then the clicking on the suggested link is a start. Going to your textbook or class notes and reviewing an example is an even better start. Note that you need to be competent in basic algebraic skills, which might be something else worth reviewing.

#### HallsofIvy

##### Well-known member
MHB Math Helper
well i really dont know because I PRESENTLY DONT KNOW ANYTHING ABOUT Differentiation using first principle but thanks anywhere
Then my question would be why are you asking this question? Aren't you taking a Calculus class? Do you know how to take a limit? Do you know how to square a binomial?