find the critical numbers of #f(x) = 2x^3+x^2+2x#?

Question

I have differentiated the equation to #6x^2+2x+2# but need help in the next steps

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Answer 1 · 2018-05-23T12:31:00

No critical numbers

Critical values occur when #dy/dx=0#

#6x^2+2x+2=0#

#3x^2+x+1=0#

#x=(-1+-sqrt(1^2-4(3)))/6#

#x=(-1+-sqrt(1-12))/6#

#x=(-1+-sqrt(-11))/6#

#x=(-1+isqrt(11))/6or(-1-isqrt(11))/6#

#f'(x)>0#

No critical numbers.

Graph:

graph{2x^3+x^2+2x [-7.9, 7.9, -3.95, 3.95]}