Answer:
Vertex → (2, 4)
Step-by-step explanation:
Quadratic equation has been given as,
y = -x² + 4x
We rewrite this equation in the form of a function as,
f(x) = - x² + 4x
By comparing this equation with the standard quadratic equation,
y = ax² + bx + c
a = -1 and b = 4
Vertex of the parabola represented by this equation is given by ![[-\frac{b}{2a}, f(\frac{-b}{2a})]](https://tex.z-dn.net/?f=%5B-%5Cfrac%7Bb%7D%7B2a%7D%2C%20f%28%5Cfrac%7B-b%7D%7B2a%7D%29%5D)
x coordinate = 
= 2
y-coordinate = f(2)
= - (2)² + 4(2)
= -4 + 8
= 4
Therefore, vertex of the given function is (2, 4)
Answer:
Step-by-step explanation:
Had the answer put don't remember
Answer:
(x-9)^2 + (y-9)^2 = 81
<u>Step-by-step explanation:</u>
<u>Step-by-step explanation:Equation of a circle</u>
( x - h )<em>^2 + </em>( y - k )<em>^2 = </em>r^<em>2 </em>
Your graph - the circle intersects the x-axis at (9 , -9)
- the circle intersects the y-axis at (9 , -9)
h = the number on the x axis intersected by the circle.
k = the number on the y axis intersected by the circle.
r = radius of the circle measured starting from the origin.
plug these in:
( x - h )^2 + ( y - k )^2 = r^2.
(x - 9)^2 + (y - 9)^2 = 9^2
(x-9)^2 + (y-9)^2 = 81
For the average to be 90,
(99 + 93 + x) / 3 = 90
or 192 + x = 270
or x = 270 - 192 = 78
Jim must score at least 78 in the third test.