Question

Find the equation of the line tangent to y = –3x^2 + x – 5 at x = –1.

Answer 1

Ok there problem sets x = to -1

Answer 2

tell me if you are here

Answer 3

Regardless, substitute -1 for x

Answer 4

\[f(-1)=-3(-1)^{2}+(-1)-5\]

Answer 5

But shouldn't you find the derivative first?

Answer 6

Do you not know how to do that?

Answer 7

I do, but wouldn't I need to do that before inserting -1?

Answer 8

Go ahead

Answer 9

tell me if you get -6x+1

Answer 10

Yeah, I got that. I just don't really understand what to do next

Answer 11

Well you need to find the points your investigating

Answer 12

(-1, 7)?

Answer 13

plug -1 into -6x+1

Answer 14

7?

Answer 15

good lol so thats your slope

Answer 16

But I thought 7 was the y-value?

Answer 17

no, you dont have the y value it only gives you the x

Answer 18

Oh haha its the tangent line

Answer 19

yes

Answer 20

the slope of the tangent line is 7

Answer 21

so is the answer 7x -1?

Answer 22

@ganeshie8 Can you help a little?

Answer 23

hold on. thats not your answer im a little lost

Answer 24

I think it might be 7x-2 but I dont know why

Answer 25

@pooja195

Answer 26

I'm not sure anymore.

Answer 27

I mean, you helped me with the slope thing which I got oddly lost on

Answer 28

I thought you knew how to do that

Answer 29

I get it now! At the time It went over my head

Answer 30

I think I got the equation now. Thank you!

Answer 31

No problem