asked 15.9k views
1 vote
Can someone lead me through the steps of rewriting the quadratic function in vertex form???

Rewrite the quadratic function in vertex form... then determine the maximum and minimum and the axis of symmetry:
y = -3x^2 + 18x - 2

asked
User Soosh
by
8.0k points

1 Answer

6 votes
complete the square
to get y=a(x-h)²+k
(h,k) is vertex
x=h is axis of symmetry
if a>0 then the verex is a minimum
if a<0 then the vertex is a maximum

so

groupu x terms

y=(-3x²+18x)-3
undistribute -3
y=-3(x²-6x)-3
take 1/2 of the liear coefient then square it
-6/2=-3, (-3)²=9
add positve and negative of that inside parentheasees
y=-3(x²-6x+9-9)-3
factor perfect squrae
y=-3((x-3)²-9)-3
expand/distribute
y=-3(x-3)²+27-3
y=-3(x-3)²+24
vertex is (3,24)
-3<0 so it is a maximum
axis of symmetry is x=3
answered
User Justin Galzic
by
8.2k points

No related questions found

Welcome to Qamnty — a place to ask, share, and grow together. Join our community and get real answers from real people.