Answer:
f(3)=56, f(-4)=277
Step-by-step explanation:
f(x)=x^4-8x-11
f(3)=3^4-8(3)-11=3*3*3*3-24-11=9*3*3-35=27*3-25=81-25=56
f(-4)=(-4)^4-8(-4)-11=(-4)(-4)(-4)(-4)+32-11=(16)(16)+32-11=256+32-11=288-11=277
By the chain rule,

which follows from
.
is then a function of
; denote this function by
. Then by the product rule,
![\dfrac{\mathrm d^2y}{\mathrm dx^2}=\dfrac{\mathrm d}{\mathrm dx}\left[\dfrac1x\dfrac{\mathrm dy}{\mathrm dt}\right]=-\dfrac1{x^2}\dfrac{\mathrm dy}{\mathrm dt}+\dfrac1x\dfrac{\mathrm df}{\mathrm dx}](https://tex.z-dn.net/?f=%5Cdfrac%7B%5Cmathrm%20d%5E2y%7D%7B%5Cmathrm%20dx%5E2%7D%3D%5Cdfrac%7B%5Cmathrm%20d%7D%7B%5Cmathrm%20dx%7D%5Cleft%5B%5Cdfrac1x%5Cdfrac%7B%5Cmathrm%20dy%7D%7B%5Cmathrm%20dt%7D%5Cright%5D%3D-%5Cdfrac1%7Bx%5E2%7D%5Cdfrac%7B%5Cmathrm%20dy%7D%7B%5Cmathrm%20dt%7D%2B%5Cdfrac1x%5Cdfrac%7B%5Cmathrm%20df%7D%7B%5Cmathrm%20dx%7D)
and by the chain rule,

so that

Then the ODE in terms of
is

The characteristic equation

has two roots at
and
, so the characteristic solution is

Solving in terms of
gives

690 because 86 is rounded up to 90
Answer:
reflection
Step-by-step explanation:
have a good Day