Question

find the derivative of 10/x as x=-12, Please explain the steps!

Answer 1

y= 10/x then find d(10x^-1)/dx

Answer 2

How would I solve it? Would distribute? :0 @EarthCitizen

Answer 3

recall the formula, that dy/dx = nx^(n-1)

Answer 4

can you help use the formula? @EarthCitizen

Answer 5

make 10/x be the inverse of x multiplied by 10 , which is 10x^(-1) then differentiate

Answer 6

since y = 10x(-1) our formula says that dy/dx = \[d(10x^-1)/dx\] therefore \[dy/dx = nx ^{n-1}\]

Answer 7

from our equation y = 10x^(-1) implies that n in the formula would be -1 therefore\[dy/dx = (-1)*10*x ^{-1-1}\]

Answer 8

Hence \[dy/dx = -10x ^{-2}\] which can also be written as \[dy/dx ={-10}/{x^{2}}\]

Answer 9

yh, check this site out it could help https://www.wolframalpha.com/input/?i=10%2Fx

Answer 10

This is a question from a practice test I took that I got incorrect and they gave me a set of multiple choice answers and that's not one of the answer choices :0 @EarthCitizen

Answer 11

yh, because you need to substitute x=-12 which should be that \[f^{\prime}(-12)= -10/{-12}^{2}\]

Answer 12

Is -10/144 one of the answers in the options ?

Answer 13

I had plugged it in and simplified and got 5/6 which is one of the answer choices but they said it was wrong

Answer 14

no here are the options 72/5, 5/72, 6/5, 5/6

Answer 15

btw, its -10/x at x=-12

Answer 16

yh, it's should be 5/72 then ?

Answer 17

how did you get that? XD

Answer 18

yh, let's have a go at it again. \[y = -10x^{-1}\]
therefore\[dy/dx = -1*-10*x^{-1-1} = 10x^{-2}\]
at x = -12 implies that \[10x^{-2} = 10/x^{2} \implies f^{\prime}(-12) = 10/(-12)^2 = 10/144 = 5/72\]

Answer 19

OHHHHHHHHHHHHH woooow!!! I'm sorry i see it now hahahaha

Answer 20

yh, hehe

Answer 21

Thank you :D

Answer 22

no p, boss