Find the inflection points of (x+2)(x-4)^2

i found the second derivative which is very long

2(x-4)2(x-4)(x+2)+(x-4)^(2)*2(x+2)+2(x-4)=0

I got one inflection point which is 4 but there must be others cause my online hw says its wrong

2. I get something quite different for the second derivative. Please reply showing your steps. Thank you!

3. Originally Posted by Asuhuman18
Find the inflection points of (x+2)(x-4)^2

i found the second derivative which is very long

2(x-4)2(x-4)(x+2)+(x-4)^(2)*2(x+2)+2(x-4)=0

I got one inflection point which is 4 but there must be others cause my online hw says its wrong
I don't know how you calculated the second derivative, but that answer is very wrong. The easiest way to differentiate $(x+2)(x-4)^2$ twice is probably to multiply it out first: $(x+2)(x-4)^2 = (x+2)(x^2-8x+16) = x^3 -6x^2 +32$. That should be easy to differentiate.