Given equation(adsbygoogle = window.adsbygoogle || []).push({});

f(x) = x^4 + 4x^3 - 2

so f ' (x) = 4x^3 + 12x^2

which simplified to

f ' (x) = 4x^2 (x+3), thus our critical points are 0 and -3

I will use this to sketch the curve

f ' (x) = 4x^2 (x+3)

Results are below.

According to my "sketch", the sequence is - , +, +, +

B means "before"

A means "after"

I used a very close number to generate this list

But I could not generate any sketch because (0,0) pair cannot have a +, +, + sequence. There must be a - sign, meaning the correct sequence should be -, +, -, +.

I need to hite (0,0) but there is no way as (-3,0) is increasing.

My calculator shows a different sequence. What is wrong with my sketch logic here?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# How do I graph this?

**Physics Forums | Science Articles, Homework Help, Discussion**