Question

b) The function f(x)=x^2-7x+1 has a tangent with the slope 3.

Calculate the equation for the tangent.

Answer 1

The tangent at what point?

Answer 2

Yep that could work. So have you found that point yet @z17 ?

Answer 3

It doesn't say. Let me check again.

Answer 4

No I was asking for the point and @Loser66 was telling you how to get it.

Answer 5

If we didn't know the slope, how would you go about finding?

Answer 6

I have the slope of 3?

Answer 7

I know, but if we didn't.

Answer 8

What does the derivative tell us?

Answer 9

Whether it's increasing or decreasing?

Answer 10

Right and doesn't it also tell you the slope?

Answer 11

Yes?

Answer 12

So find the derivative of your function

Answer 13

Is it x^2?

Answer 14

Your function is x^2-7x+1
I'm asking you to find the derivative of it so we can get the slope.

Answer 15

What is the derivative of x^2?

Answer 16

Do you know the power rule?

Answer 17

Yes, it just takes me time to calculate it.

Answer 18

The power rule says the derivative of x^n is nx^(n-1)

Answer 19

I'm so confused to be honest

Answer 20

So you don't know the power rule then?

Answer 21

Do you know the formal definition of a derivative?

Answer 22

dy/dx ?

Answer 23

Yes what is the formal definition?

Answer 24

Don't remember -.-

Answer 25

\[f'(x)=\lim_{h \rightarrow 0}\frac{f(x+h)-f(x)}{h} \text{ formal definition } \]

Answer 26

or you could use:
\[f'(a)=\lim_{x \rightarrow a}\frac{f(x)-f(a)}{x-a}\]

Answer 27

So what do I do in order to calculate the equation?

Answer 28

I'm still trying to get you to find the derivative of x^2-7x+1
This is step one. We haven't got passed it yet.

Answer 29

and I do that by using the power rule right?

Answer 30

You could but it didn't appear you knew it.

Answer 31

And then there is also constant multiple rule and constant rule.

Answer 32

So that is why I was going a step backwards to the actual definitions.

Answer 33

Since you didn't know the power rule.

Answer 34

How do I apply the power rule to find the 1st derivate?

Answer 35

\[\text{ power rule } (x^n)'=nx^{n-1} \]

Answer 36

Use this rule to find the derivative of x^2

Answer 37

what is n?

Answer 38

When is x^2 equal to x^n?

Answer 39

I don't know

Answer 40

I need to study

Answer 41

so you do know that x^2 equals x^2

Answer 42

so if i asked you when does x^2 equal x^n you would say when n equals ?

Answer 43

x^2?

Answer 44

and what value of n are you stating?

Answer 45

\[x^2=x^n => n=? \]

Answer 46

What do mean by value of n? I'm not used to studying math in english.