College Algebra
posted by Brianna .
Let g(x) = 2x2 + bx + c be a quadratic function, defined everywhere, where b and c are constants. If x = 1 marks the location of one of the zeros of this quadratic function, and if the yintercept of this function is at (0, 5), then use this information to name constant b.

g ( x ) =  2 * x ^ 2 + b * x + c
For:
x = 0
y= 5
Then:
g( x ) =  2 * 0 ^ 2 + 0 * x + c = 5
g( x ) = c = 5
c = 5
For:
x= 1
y = 0
g ( x ) =  2 * 1 ^ 2 + b * 1 + c = 0
g ( x ) =  2 + b + c = 0
g ( x ) =  2 + b + 5 = 0
g ( x ) = b + 3 = 0
b = 3