Question

find the slope of the tangent line to the graph of the following function and determine its equation in the slope intercept form: f(x)=3x-x^2 at (-2,-10)

Answer 1

sorry - I meant the tangent line is found by differentiating the equation

Answer 2

do you know how to differentiate?

Answer 3

finding derivative?

Answer 4

yes

Answer 5

find derivative of f(x). ok

Answer 6

so the f'(x)=3-2x

Answer 7

correct

Answer 8

so then now i plug in the x value: 3-2(-2)=7

Answer 9

so is this my m?

Answer 10

yes

Answer 11

so now you know the line has the form:
y = 7x + c

you alos know it passes through (-2, -10) so you should now be able to calculate c.

Answer 12

*also

Answer 13

yes it's 4! thanks you

Answer 14

so the eqn is y=7x+4

Answer 15

correct - well done!

Answer 16

BTW: you can also use wolfram to check your answers, e.g. see here: http://www.wolframalpha.com/input/?i=tangent+to+y%3D3x-x^2+at+%28-2%2C+-10%29

Answer 17

thank u

Answer 18

yw