+71 x+4/x2
Can someone show how they get a minimum turning point of (2,3) and it has no points of inflextion
Thank you so much
+129962 y = x + 4/x^2
Write as
y = x + 4x^(-2)
y ' = 1 - 8x^(-3)
Set this = 0
1 - 8x^(-3) = 0
1 = 8 / x^3 multiply both sides by x^3
x^3 = 8 ⇒ x = 2
And when x = 2, y = 2 + 4 /(2)^2 = 2 + 1 = 3
Take the second deriviative
y'' = 24x^(-4) = 24 / x^4
Putting 2 into this gives a positive.....so....this indicates that (2,3) is a minimum
Here"s the graph : https://www.desmos.com/calculator/3xcrgvdoyl
