darkrider2001

wow thanks i get it now

can anyone help me i have to go to bed soon and this is due tommorow.

sorry i think i posted this in the wrong place.

he question was: Rolle's Theorem: f(x) = x3 + x2 [-1, 1] (It had some other stuff about finding all x values where the theorem applies) My work: f`(x) = 3x2 + 2x f(x) is continuous on interval [-1,1] and f`(x) is continuous on interval (-1,1) I know f(-1) != f(1) (not equal) but I did this, f(x)=x3 + x2 = x2(x + 1) = 0 x=0; x=-1 0 and -1 are inside the continuous interval [-1,1] and f(0) = f(-1) = 0 So Rolle's theorem applies! Now we know there is some point on [-1,1] where f`(x)=0 f`(x) = 3x2 + 2x = x(3x + 2) x=0 ; x=-2/3 Ok that was pretty much the work I had on my paper. My friend said it does not apply because f(-1)!=f(1) (not equal) and he told me he got the problem right (he did the quiz the other week) I just did this quiz this afternoon after school, so I haven't gotten it back yet. I'm sure it's right as I swear I saw one of the sources I'm studying from do a similar problem in almost the exact same way. However, tomorrow is the last day of class, and I'm unsure if she'll check it right. I think it's right, but in case if she checks it wrong, can someone give me some kind of proof as to why it's right. Much thanks to anyone who helps as this is very important for my grade.

my names alex and im studying calculus and I looking for some help thanks =D