Question

Rewrite the equation in vertex form. Name the vertex and y-intercept.
y = x^2 – 10x + 15


y = (x – 10)^2 –10
vertex: (–10, –10)
y-intercept: (0, –10)

y = (x – 5)^2 – 10
vertex: (5, –10)
y-intercept: (0, 15)

y = (x – 5)^2 + 40
vertex: (5, –10)
y-intercept: (0, 15)

y = (x – 10)^2 + 20
vertex: (–10, –10)
y-intercept: (0, –10)

Answer 1

y = x^2 – 10x + 15

write down this equation in the form of
(y-a)= b(x-c)^2

Answer 2

can u do this?

Answer 3

I have no idea how , sorry . :/

Answer 4

1st write the rhs in the form of complete square..
y = x^2 – 10x + 15
y={ x^2 – 10x +25} -25+15

Answer 5

now u can do this?

Answer 6

y={ x^2 – 10x +25} -25+15
y=(x^2 – 10x +25)-10
(y+10)=(x^2 – 10x +25)

Answer 7

fine?

Answer 8

now rhs is a complete square..

Answer 9

im soo confused?

Answer 10

oh...ok
let me start again...

Answer 11

u have been given an equation
y = x^2 – 10x + 15
and asked for vertex?

Answer 12

do u know..what this equation represent if u plot this on a graph?

Answer 13

you mean like quadratic ?

Answer 14

if u plot a quadratic equation...what u'll get?
like straight line, circle , parabola...

Answer 15

suppose u plot y=x+3, u'll get a straight line...right?

Answer 16

right

Answer 17

so if u plot y = x^2 – 10x + 15
then wat u'll get?

Answer 18

straight line?

Answer 19

i dont think so ?

Answer 20

ok...u'll get a parabola.

Answer 21

and u know that parabola has a vertex?

Answer 22

i didnt know that , but now i do . lol

Answer 23

does it make a sense?

Answer 24

kinda . doesnt x^2 make it look like that ?