Verified answer

f⁡x=3⁢x^3+2⁢x^2+C⁢x+4

fx=3x^3+2x^2+cx+4

x=27x+4x+x+4

x=32x+4

-31x=4

x=4/-31

Hope I helped!

Maxwell

f(x) = 3x^3 + 2x^2 + cx + 4 f ' (x) = 9x^2 + 4x + c equate f ' (x) tp 0 9x^2 + 4x + c = 0 => x^2 + (4/9)x + c/9 = 0 ( x + 2/9)^2 - 4/80 one + c/9 = 0 with a view to have purely one serious extensive style, c/9 might desire to be 4/80 one c/9 = 4/80 one c = 4/9