Find critical points for y'=2/3x^3-4x

To find the critical points of the function y' = (2/3)x^3 - 4x, we need to first find the derivative, and then set it equal to zero.

1. Take the derivative of the function:
To find the derivative of y', we can use the power rule for differentiation. According to the power rule, the derivative of x^n is nx^(n-1).

dy/dx = d/dx (2/3)x^3 - 4x
= (2/3)(d/dx)(x^3) - (d/dx)(4x)
= (2/3)(3x^2) - 4
= 2x^2 - 4

2. Set the derivative equal to zero:
Now, we set the derivative equal to zero and solve for x to find the critical points:

2x^2 - 4 = 0

Adding 4 to both sides, we get:

2x^2 = 4

Dividing both sides by 2, we get:

x^2 = 2

Taking the square root of both sides, we obtain two solutions:

x = √2 and x = -√2

So, the critical points are x = √2 and x = -√2.