I'm not sure how to factor x^3-4x is greater than/equal to 0 so that I can find the zeroes. Can you demonstrate, please?

Answer 1

x³-4x
=x(x²-4)
=x(x+2)(x-2)

A few identities that may help you while you're on the subject:

A²-B²=(A+B)(A-B)
A³-B³=(A-B)(A²+AB+B&sup2)
A³+B³=(A+B)(A²-AB+B&sup2)
A&#8308-B&#8308
=(A²+B&sup2)(A²-B&sup2)
=(A²+B&sup2)(A+B)(A-B)