Which is the axis of symmetry of a parabola with equation x^2=-4y?
x = –4
x = –1
x = 0
x = 1

The axis of symmetry is

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

and the axis of symmetry is the x-coordinate of the vertex

In this problem we have

The vertex is the origin

therefore

the axis of symmetry is

were is the equation

answer set (b) 0.5, 3/4 80% is in order from least to greatest.  

step-by-step explanation:

in order to compare rational numbers to each other, it is much easier if they are in the same form.   typically, the best form in which to evaluate rational numbers is in decimals.   in order to convert a percent to a decimal, you would divide the given percentage by 100.   you can also accomplish the conversion by moving the decimal point over two places to the left.   for example, the decimal value of 80% is 80/100, or 0.8.   in order to convert a fraction to a decimal, you need to divide the numerator by the denominator.   for example, 3/4 is 0.75.   so, for choice (b) 0.5 3/4 (0.75), 80% (0.8) is the only choice in which the numbers are in order from least to greatest.