I just want to make sure I got it right.
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Inflection points occur when the second derivative is 0, so first we find the second derivative:
f(x) = 2x^3 - 12x^2 + 8x - 4
By the power rule:
f '(x) = 6x^2 - 24x + 8
Again by the power rule:
f ''(x) = 12x - 24
So, we have our second derivative, and we let it equal 0 to find the x-coordinate of the (in this case only) inflection point:
12x - 24 = 0
Add 24:
12x = 24
Divide by 12:
x = 2
So, our x-coordinate is x = 2, plug this into the original equation to find the y-coordinate at this point:
f(2) = 2(2)^3 - 12(2)^2 + 8(2) - 4
Solve:
f(2) = 2(8) - 12(4) + 16 - 4
f(2) = 16 - 48 + 12
f(2) = -20
So, the point is (2, -20), you are correct!
f(x) = 2x^3 - 12x^2 + 8x - 4
By the power rule:
f '(x) = 6x^2 - 24x + 8
Again by the power rule:
f ''(x) = 12x - 24
So, we have our second derivative, and we let it equal 0 to find the x-coordinate of the (in this case only) inflection point:
12x - 24 = 0
Add 24:
12x = 24
Divide by 12:
x = 2
So, our x-coordinate is x = 2, plug this into the original equation to find the y-coordinate at this point:
f(2) = 2(2)^3 - 12(2)^2 + 8(2) - 4
Solve:
f(2) = 2(8) - 12(4) + 16 - 4
f(2) = 16 - 48 + 12
f(2) = -20
So, the point is (2, -20), you are correct!