Core surds help plz :-)

Hi, In a textbook it says:
" Show that if neither x nor y is equal to 0, then root x and y is never equal to root x and root y."
I dont understand this question at all, i'm in year 12. someone please simplify this question and help me with this please!!
Thankyou

Reply 1

ValerieKR

10

Original post by Chelsea12345

Hi, In a textbook it says:
" Show that if neither x nor y is equal to 0, then root x and y is never equal to root x and root y."
I dont understand this question at all, i'm in year 12. someone please simplify this question and help me with this please!!
Thankyou

That can't be what it says exactly - what does it say exactly? Is there another part of the question?
By and do you mean plus?

(edited 7 years ago)

Original post by Chelsea12345

Hi, In a textbook it says:
" Show that if neither x nor y is equal to 0, then root x and y is never equal to root x and root y."
I dont understand this question at all, i'm in year 12. someone please simplify this question and help me with this please!!
Thankyou

Huh?

\sqrt{xy}=\sqrt{x} \cdot \sqrt{y}

If neither root x nor root y is equal to 0, then root of xy is not 0.

Reply 3

Chelsea12345

OP

12

Original post by ValerieKR

That can't be what it says exactly - what does it say exactly? Is there another part of the question?

" Show that If neither x nor y is equal to 0 , then √x+y is never equal to √x + √y."

Reply 4

ValerieKR

10

Original post by Chelsea12345

" Show that If neither x nor y is equal to 0 , then √x+y is never equal to √x + √y."

square both of them
the first one you get
x+y
the second one you get x+y+2root(xy)

subtract them to find the difference
2root(xy)
they are equal when this = 0
2root(xy)=0
root(xy)=0
xy=0
x or y = 0

therefore if neither x nor y is 0 the difference cannot be 0 and they cannot be equal

Core surds help plz :-)

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you