Question

For what value(s) of is the tangent line of the graph of f(x)=6x^3-36x^2+53x-18


parallel to the line y=-x+1.6?

If there is more than one value of , list them as a comma separated list.

Answer 1

ok so this is very similar to the last problem. except instead of a slope of zero (horizontal line), they want you to find the points where the graph has slope equal to the slope of the line y=-x+1.6.

that's what they mean by parallel. they mean a line with the same slope. since the equation is in the nice form :D y=mx+b.. what is the slope of that line?

Answer 2

-1

Answer 3

boo ya! so do the same thing as last time. find an equation for the tangent line.
then figure out when f'(x) = -1

Answer 4

I find the derivative of f(x)=6x^3-36x^2+53x-18 right?

Answer 5

yes

Answer 6

18x^2-72x+53?

Answer 7

looks good. so f'(x) = -1 = 18x^2-72x+53, solve for x :o

Answer 8

143

Answer 9

hmmmm not so much :O

Answer 10

i substitute -1 in right? or do i factor it out?