discriminant (1 Viewer)

[mtsmahia]

Hi Guys,

Can someone please help with this Q

Q) Find the values of p if px^2 -2x +3p=0 is a negative definite, giving exact values.

The answer is p less than -root 3/3.
I got a different answer for some reason

Thanks

 

[Timothy.Siu]

Hi Guys,

Can someone please help with this Q

Q) Find the values of p if px^2 -2x +3p=0 is a negative definite, giving exact values.

The answer is p less than -root 3/3.
I got a different answer for some reason

Thanks

negative definite...so discriminant is <0 and p is <0 (since its NEGATIVE definite)

discr.=4-12p^2
4-12p^2<0
p^2 >1/3

p>1/root3 or p<-1/root3

so, p<-1/root3

 

[mtsmahia]

negative definite...so discriminant is <0 and p is <0 (since its NEGATIVE definite)

discr.=4-12p^2
4-12p^2<0
p^2 <1/3

-1/root3 < p <1/root3

so, -1/root3< p <0
hmm, is this what u got?

Ya!! I got p< -1/root 3

but for some reason the asnwers says p<- root 3/3

:mad1:

 

[Timothy.Siu]

Ya!! I got p< -1/root 3

but for some reason the asnwers says p<- root 3/3

:mad1:

ohhh, they're equal.

-1/root3 x root3/root3=-root3/3

 

[Lukybear]

I think its actually, p<-1/root3.

Timothy forgot to change signs when doing division.

p^2>1/3
p= 1/root3 or -1/root3

Solve via graph.
p>1/rt3 or p<-1/rt3
since it is negative def, p<0
thus p<-1/rt3.

 

[mtsmahia]

ohhh, they're equal.

-1/root3 x root3/root3=-root3/3

OH Right

 

[Timothy.Siu]

I think its actually, p<-1/root3.

Timothy forgot to change signs when doing division.

p^2>1/3
p= 1/root3 or -1/root3

Solve via graph.
p>1/rt3 or p<-1/rt3
since it is negative def, p<0
thus p<-1/rt3.

nah i just did a mistake. i guess u can look at it that way though.

but yeah i changed it.