Question

Consider the function f(x)=x^2+5x+5 and the point A(4,5).

f′(x)=_______

Find a formula for the slope of a line passing through point A, and an arbitrary point on the function. Your answer should be a formula in terms of x.
slope=_________

Using your answers from the two previous questions, find the slope(s) of the line(s) through point A that is (are) tangent to f(x). If there is more than one line you can separate your answers with a comma (ex. 5,2 ).
slope(s)=_____________

Answer 1

I know that f'(x) = 2x+5. But I dont know where to start with the second and third part. Any help would be greatly appreciated!!

Answer 2

u r right f'(x) = 2x+5.

Answer 3

(5-(x^2+5x+5 ))/(4-x) =(-x^2-5x)/4-x
=(x^2+5x)/x-4

Answer 4

you could substitute x as 4 in 2x+5, so that you'll get the f'(x). which is equivalent to slope

Answer 5

@darkmare got it that's the answer for second question

Answer 6

how did you know what to do to find the equation for the slope?

Answer 7

where did the x^2+5x_5 come from?

Answer 8

simple one point is A(4,5) arbitary point is (x,y) i.e (x,x^2+5x+5 ) find the slope of these two points

Answer 9

oooo ok

Answer 10

so how would I figure out the last part?

Answer 11

is the answer for last part is 13

Answer 12

no i know its not 13

Answer 13

k just wait i will find it

Answer 14

for #3, answers are 25,1

Answer 15

I just figured that out :) Thanks for your help guys!! :)

Answer 16

right