What is the vertex form of y=7x^2 +3x + 5 ?

1 Answer
Jan 6, 2016

y = 7(x + 3/14)^2 + 917/196

Explanation:

The vertex form of a quadratic equation y=ax^2 +bx +c is y=a(x+m)^2 +n, where m = b/(2a) and n = -a(b/(2a))^2 + c
Then the vertex is at the point where the bracketed expression is zero and is therefore (-m,n)
Therefore y = 7(x+3/14)^2 -7*9/196 +5
y = 7(x +3/14)^2 - (63 + 980)/196
y = 7(x + 3/14)^2 + 917/196