Question

Find the derivative for the following functions:
Please do not simplify answer

Answer 1

\[y=(x^3-7x^2-x)(3x+5)\]

Answer 2

Use the product rule ahaha

Answer 3

I tried it but it doesnt look right

Answer 4

Can you show me what you got after trying?

Answer 5

sure

Answer 6

\[y=(x^3-7x^2-x)(3)+(3x+5)(1)\]

Answer 7

I understand where you got the (3), but where did you get the (1) from?

Answer 8

from x^3

Answer 9

Oh so I know where your problem is

Answer 10

Let's revise the basic stuffs of differentiation first :)

Answer 11

okay

Answer 12

Firstly is the derivative of x

Answer 13

I think you know this right?

Answer 14

yes

Answer 15

oh wait wasn't it suppose to be 3x because i need to multiply 1x3 from its exponent

Answer 16

Well 3x is still incorrect, let's continue revising :p

Answer 17

What's the derivative of \(\Large x^2\)?

Answer 18

okay

Answer 19

2x

Answer 20

And the derivative of \(\Large x^3\)?

Answer 21

3x^2

Answer 22

Exactly :)

Answer 23

Now what's the derivative of, say, \(\Large7x^2\)?

Answer 24

14x

Answer 25

Now, what's the derivative of \(\Large x^3−7x^2−x\)?

Answer 26

\[3x^2-14x\]

Answer 27

Nope, try again please? The derivative of \(x\) isn't 0 :)

Answer 28

\[3x^2-14x-1\]

Answer 29

Yep, you're getting it :)

Answer 30

So, back to the question

Answer 31

The derivative of f(x)g(x) is f'(x)g(x)+g'(x)f(x)

Answer 32

so it will be \[(3x^2-14x-1)(3x+5)+g'(x)f(x)\]

Answer 33

Well no.

Answer 34

i dont know what to do for (3x+5)

Answer 35

Wait, sorry for the "no", you're actually on the right track

Answer 36

I overlooked at something haha

Answer 37

You find its derivative

Answer 38

so it will be 3

Answer 39

My formula in words: The derivative of the product of two functions is the first function multiplied by the derivative of the second function plus the second function multiplied by the derivative of the first function.

And yes.

Answer 40

\[(3x^2-14x-1)(3x+5)+(3)(x^3-7x^2-x)\]

Answer 41

I guess this is correct

Answer 42

Yes this is correct

Answer 43

do you mind helping me with other ones

Answer 44

Okay, but please open a new post.

Answer 45

okay hold on