Question

CALCULUS PROBBBBBSSSS!

f(x)= x^4 - 2x^3 - x^2 - 4x + 3
I= [0,4]
MAX AND MIN

Answer 1

find derivative

set it equal to 0

Answer 2

I'm so fast that last night I turned off the light switch in my hotel room and was in bed before the room was dark.

Answer 3

also, since this is a closed interval you're looking at, evaluate at the enpoints of the interval...

Answer 4

@satellite73 , Cassius Clay

Answer 5

i got
4x^3 - 6x^2 -2x - 4
now what??

Answer 6

aka imranmeah

Answer 7

??? never heard of 'em

Answer 8

try something obvious like x = 1, x = -1, x = 2
you will get it on the third try

Answer 9

shut up satellite73 THIS IS MATH ONLY

Answer 10

how you are supposed to know that i am not sure, but \(x=2\) is a root of the derivative

Answer 11

huh

Answer 12

\[f'(x)=4x^3 - 6x^2 -2x - 4 \]
\[f'(2)=0\] is the critical point

Answer 13

so your last job is to take
\[f(0), f(2), f(4)\] to find the max and min

Answer 14

how did you get x = 2???

Answer 15

Also, graphing it might help at the end points 0 and 4. See the attached

Answer 16

\[4 x^3-6 x^2-2 x-4=2 (x-2) \left(2
x^2+x+1\right)\]

Answer 17

i cheated.

but you should try the obvious possibilities first. if you have a rational zero, then the numerator must divide 4 and the denominator must also divide 4. since this problem was cooked up by some math teacher 2 works out. that is why i suggested try 1 and -1 first because they are easiest to check.

you can try to factor as eliassab did, but honestly i have no idea how to factor a cubic polynomial without knowing one of the roots.

Answer 18

Knowing one root r than dividing by (x -r) will help you factor your cubic.

Answer 19

THANK YALLLLL!!!! much love!!