# How do you write the quadratic function in vertex form given vertex (2,-1) and point (4,3)?

##### 1 Answer

May 12, 2017

#### Explanation:

#"the vertex form of a quadratic function is."#

#color(red)(bar(ul(|color(white)(2/2)color(black)(y=a(x-h)^2+k)color(white)(2/2)|)))#

where ( h , k ) are the coordinates of the vertex and a is a constant.

#"here " (h,k)=(2,-1)#

#rArry=a(x-2)^2-1#

#"to find a, substitute the point "(4,3)" into the equation"#

#rArr3=a(4-2)^2-1#

#rArr4a=4rArra=1#

#rArry=(x-2)^2-1larrcolor(red)" in vertex form"#