What is the y-intercept of y = ax^2 + bx + c?

What is the y-intercept of y = ax^2 + bx + c?

• A. a
• B. c
• C. b
• D. 0

Answer: (B)

The y-intercept is found where the graph crosses the y-axis, which is when x is 0. Plugging x = 0 into y = ax^2 + bx + c gives y = a·0^2 + b·0 + c = c. So the intercept is at (0, c). The terms with x vanish at x = 0, leaving just the constant term. If c happens to be zero, the intercept would be at the origin, but in general it is c.

The y-intercept is found where the graph crosses the y-axis, which is when x is 0. Plugging x = 0 into y = ax^2 + bx + c gives y = a·0^2 + b·0 + c = c. So the intercept is at (0, c). The terms with x vanish at x = 0, leaving just the constant term. If c happens to be zero, the intercept would be at the origin, but in general it is c.