#NEED HELP ON C

1 messages · Page 1 of 1 (latest)

past orbit
#

<@&791435371564892232>

crystal island
past orbit
#

yes ty

crystal island
#

youve shown the discriminant of f(x) is (k+a)^2 + b

past orbit
#

yep

crystal island
#

do you know what b is by any chance

#

is it positive

past orbit
#

i got (k+1)^2+8

crystal island
#

ok awesome

#

so do you know what the discriminant tells you

past orbit
#

OH

crystal island
#

about the roots

past orbit
#

oh

#

he said he done a and b

past orbit
crystal island
#

when

#

so discriminant says

#

if disc > 0 then it has distinct real roots

#

if its = 0, it has 1 repeated real root

past orbit
#

yep

crystal island
#

< 0 means no real solns

#

ok so

past orbit
#

but i solved for k and it gave me a negative surd

crystal island
#

youve shown the discriminant is (k+1)^2 + 8

#

and we wanna know if this is positive or not

#

yeah

past orbit
#

ah ok ok

crystal island
#

ok so

#

what can you tell me about

#

the positivity of (k+1)^2

#

is it positive or negative or both or what

#

or 0

past orbit
#

hmmm something squared should always be positive

crystal island
#

yeah so

past orbit
#

and it should be over 0

#

cos u add 1

#

so >0

crystal island
#

any number squared is always positive, UNLESS its 0^2

#

which is0

past orbit
#

but then k+1

crystal island
#

k can be anything so

#

yeah what if k=-1

past orbit
#

ahhhhh

#

i see ur point

crystal island
#

so its 0 or more

#

not positive but

past orbit
#

i see

crystal island
#

definitely >= 0 yeah

#

ok but

#

you actually have (k+1)^2 + 8

past orbit
#

yes so i'm confused as to what to do next

crystal island
#

ok so well if

#

(k+1)^2 >= 0

#

then surely

past orbit
#

adding 8

crystal island
#

(k+1)^2 + 8 >= 8

#

right?

past orbit
#

hmmmmm

crystal island
#

adding 8 to both sides

past orbit
#

yes ok i can see that

crystal island
#

if something is >=0 then 8 more than that is definitely >= 8

past orbit
#

ah ok that makes sense cos we know the lowest value will always be 0

crystal island
#

and 8 is definitely >0

#

exactly

past orbit
#

yep

crystal island
#

and then you can just quote

#

"discriminant > 0 means distinct roots"

past orbit
#

two distinct roots ah ok ok

#

ok thanks

#

which uni do u go btw

crystal island
#

nw!

#

oxf

past orbit
#

oxford!!

#

damn congrats

crystal island
#

doing maths 😭

#

(and stats)

past orbit
#

my teacher went there lol

crystal island
#

eyyy nice

past orbit
#

did the same degree as u

crystal island
#

another mega nerd

past orbit
#

my other teacher went to warwick

crystal island
#

some of my friends are at warwick

#

pretty good from what ive heard