# How do you find the important parts of the equation to graph the function #y = -x^2 + 3#?

##### 1 Answer

Jan 15, 2017

Refer the explanation section

#### Explanation:

Given -

#y=-x^2+3#

Find the vertex first-

If the quadratic equation is in the form

#x=(-b)/(2a)#

Since there is no

#y=-x^2+0x+3#

#x=(-(0))/(2 xx (-1))=0#

At

#y=-0^2+3=3#

The vertex is

Then we have to decide whether the curve is concave downwards or upwards. That is given by the second derivative.

#dy/d=-2x#

#(d^2y)/(dx^2)=-2<0#

Since the second derivative is less than zero, the curve is concave downwards.

Take two points to the right of zero [ x-coordinate of the vertex] and two points to the left of zero. Find the corresponding

Plot the pairs in a graph sheet. Join all the points.