How do you write the quadratic in vertex form given vertex is (1/10, -9/10) and y intercept is -1?
Standard form f(x) = ax^2 + bx + c
First find a, b, and c. We have as information:
x of vertex:
y intercept (-1) gives -> c = -1
y of vertex:
a + 10b - 100 + 90 = 0 -> a + 10b - 10 = 0 . Replace a by -5b
-5b + 10b = 10 -> b = 10/5 = 2 -> a = -10.
Finally, vertex form:
Check: Develop f(x)