Answer:
Step-by-step explanation:
1) The equation of circle having center at origin:
x² + y² = r²
Where 'r' is the radius.
diameter = 36
r = 36 ÷ 2 = 18
Equation of circle :
x² + y² = 18²
x² + y² = 324
Option d.
2) Find the discriminant D.
If D > 0, then the quadratic equation has two distinct real roots.
If D= 0, then the quadratic equation has two identical real roots.
If D < 0, then the quadratic equation has no real roots.
D = b² - 4ac
x² - 6x + 9 = 0
a = 1 ; b = -6 ; c = 9
D = (-6)² - 4*1*9
= 36 - 36
D = 0
As D = 0, the quadratic equation has two identical real roots
Option a.
3) The axis of symmetry of a parabola is the vertical line passing through the vertex. It will be middle of the x-intercepts.
X- intercepts are -8 , 2
( -8 + 2 ) ÷ 2 = -6 ÷ 2 = -3
x = - 3
Option d.
