# What is the axis of symmetry and vertex for the graph #y = -x^2 – 2x – 13#?

##### 1 Answer

May 4, 2017

#### Explanation:

#"for the standard quadratic function " y=ax^2+bx+c#

#"equation of axis of symmetry is " x=-b/(2a)=x_(color(red)"vertex")#

#"for " y=-x^2-2x-13#

#"then " a=-1,b=-2" and " c=-13#

#"equation of axis of symmetry " =-(-2)/(-2)=-1#

#rArr" axis of symmetry " x=-1#

#"substitute this value into function and evaluate for y"#

#y_(color(red)"vertex")=-(-1)^2-2(-1)-13=-12#

#rArrcolor(magenta)"vertex " =(-1,-12)#