Where is g prime of x equal to zero? G prime of x is equal to zero when, let's just take g prime of x. We're gonna leverage the power rule right here. Four x to the third power, four x to the third minus five x to the fourth, minus five x to the fourth is equal to zero. Let's see, we can factor out an x to the third. We have x to the third times four minus five x is equal to zero. So this is going to happen when x is equal to zero.