Question

Can someone please help me find the maximum and minimum for this calculus problem.
f(x) = x^4-2x^3-x^2-4x+3
I=[0,4]

Answer 1

as usual, exrema occur when the derivative is equal to zero, or at the endpoints

Answer 2

hence, take the derivative, set it to zero, and solve for x
then check those values in the original equation
you must also compare them to the values at the endpoints (f(0) and f(4))

Answer 3

can someone work it out for me and show me step by step what to do?

Answer 4

step 1)
take the derivative with respect to x

Answer 5

...tell me what you get

Answer 6

taking the deivative i got 4x^3-6x^2-2x-4

Answer 7

Now set it to zero and solve for x

Answer 8

how do you solve for polynomials like that?

Answer 9

i always get lucky with simpler ones where i can use the quadratic formula n' stuff

Answer 10

You can factor it, but that could take awhile. Put it in Wolfram Alpha to find x. After you find X, put the value of x into the 2nd derivative to determine if you have a max or min.

Answer 11

but you can't just use wolfram during an exam! com'on now

Answer 12

You can put it into a graphing calculator though

Answer 13

i should learn how to use one of those roflmao

Answer 14

If you can't use a graphing calculator you can just factor and solve

Answer 15

can someone work it out for me?

Answer 16

You said that you found the derivative to be: 4x^3-6x^2-2x-4, so equate it to zero...
4x^3-6x^2-2x-4=0
We find x to be 2.
Take the second derivative, plug in 2 for x and if we get a negative, then it is a maxima, if we get a positive number, then it is a minimum

Answer 17

thank u