Question

Find the slope of the line tangent to the graph at the given point.

y= 2/4+x, x=8

What formula do I use to solve this one?

Answer 1

this is the same as the last one. Just take the derivative first. then plug in 8 for x to get a slope

Answer 2

d(u/v)=u'v-v'u/v^2 ? then substitute for u', v, v'?

Answer 3

\(\dfrac{d}{dx}(2/4+x) = \dfrac{d}{dx}(1/2 + x) = 1\)

The slope of ALL tangent lines is 1.

If you meant some other function, you will have to write it correctly.

Answer 4

The answer is -1/72. I'm just not sure how to get to it.

Answer 5

it cant be if the equation is what you provided

Answer 6

First, write it correctly. You need y = 2/(4+x). The parentheses are NOT optional.

Answer 7

good catch @tkhunny

Answer 8

from there y = 2(4+x)^-1 find the derivative of this

Answer 9

can you do that

Answer 10

Not really. The -1 is confusing me.

Answer 11

its just a power, so use the power rule.
y' = 2(-1)(x+4)^(-1-1)

Answer 12

Ah, okay. I remember now.

Answer 13

Thanks!

Answer 14

no problem