Time remaining:
why x=y2-5y is not a function but y x2-5 is

label Mathematics
account_circle Unassigned
schedule 1 Day
account_balance_wallet $5

So the question is asking why x=y2-5y is not a function but x=y2-5y is not. The question also says to substitute -6 with x to solve for 1. (the 2 is an exponent just so you know). I solved y=66 in the first one, but got -1 for the second...??

Sep 8th, 2014

1)   x = y^2 - 5y  ,  x = - 6

  - 6 = y^2 - 5y

 y^2 - 5y + 6 = 0

(y - 2)(y - 3) = 0  ,  factorise

y-2 = 0 or  y - 3 = 0 

 y = 2  , y = 3

( -6 , 2 ) & ( -6 , 3 ) are the points 

- 6 has two images 2 & 3

not a function as x cannot have two different images

2)   y = x^2 - 5

 x = - 1

  y = ( - 1)^2 - 5

   y = 1 - 5 = - 4

  (- 1 , - 4 )

- 1 has only one image so it's a function 

Sep 8th, 2014

Studypool's Notebank makes it easy to buy and sell old notes, study guides, reviews, etc.
Click to visit
The Notebank
...
Sep 8th, 2014
...
Sep 8th, 2014
Jun 25th, 2017
check_circle
Mark as Final Answer
check_circle
Unmark as Final Answer
check_circle
Final Answer

Secure Information

Content will be erased after question is completed.

check_circle
Final Answer