given the quadratic funtion y=-2x+4x+5 what is the direction of opening?

Question

quadratic functions

Answer 1

The general form of a quadratic equation is:

 

y = ax² + bx + c

 

If a > 0, then the parabola opens upward with the vertex at the bottom.  If a < 0, then the vertex is at the top and parabola opens downward (an inverted parabola).  In your case:

 

y = -2x² + 4x + 5

 

a = -2, so it is less than zero and opens ___________?

Answer 2

This is not a quadratic function. A quadratic function is a second degree polynomial in the the form:

 

y=ax²+bx+c

 

Unless, this is a typo leaving off the squared term in the first term of your function being -2x with intended to being -2x². One rule of thumb I'll give you is the sign of the coefficient of the squared variable determines which direction the parabola opens up. A positive coefficient opens the parabola upward and a negative coefficient opens it downward.