How do I know when a quadratic function crosses the y-axis?
The key thing to remember here is that the y-axis is a straight line and all of the points that lie on it have the x-value of 0. This means that the curve crosses the y-axis when x=0 so you can substitute this into the function to calculate the y value.For example, if y = x2 + 6x + 8, we would substitute x with 0 to calculate y.y = x2 + 6x + 8y = 02 + 6(0) + 8y = 0 + 0 + 8 = 8Therefore the function crosses the y-axis when x is 0 and y is 8, the co-ordinate (0,8).
SR
Related Maths GCSE answers
All answers ▸Solve the quadratic equation 4x^2 - 5x -6 = 0
Expand and simplify: (5w-6)(2w+7)
How do you solve the following simultaneous equations? Equation 1: 2x + 3y = 13 Equation 2: 3x - y = 3
Electricity: 23.15 cents p/day plus 13.5 cents p/unit used Gas price: 24.5 cents p/day plus 5.5 cents p/unit used (a)(i) In 90 days, a family used 1885 units of electricity. Calculate the total cost, in dollars, of the electricity they used.