Which function has a vertex on the y-axis?
f(x) = (x – 2)2
f(x) = x(x + 2)
f(x) = (x – 2)(x + 2)
f(x) = (x + 1)(x – 2)

Step-by-step explanation:

we know that

The equation of a vertical parabola into vertex form is equal to

where (h,k) is the vertex of the parabola

If the vertex is on the y-axis

then

the x-coordinate of the vertex is equal to zero

so

substitute

therefore

the vertex is the point

This function has the vertex on the y-axis

see the attached figure to better understand the problem

∠acb = 8°

step-by-step explanation:

∠xba lies on the circle and is half the measure of the intercepted arc ax

hence

measure of arc ax = 2 × 42° = 84°

∠acb is outside the circle and is

∠acb = (arcab - arcax ), hence

∠acb = 0.5 (100 - 84) = 0.5 × 16° = 8°