Answer:
r = 10 , centre = (6, - 2 )
Step-by-step explanation:
the equation of a circle in standard form is
(x - h)² + (y - k)² = r²
where (h, k ) are the coordinates of the centre and r is the radius
given
x² - 12x - 60 = - y² - 4y ( add y² + 4y to both sides )
x² - 12x + y² + 4y - 60 = 0 ( add 60 to both sides )
x² - 12x + y² + 4y = 60
using the method of completing the square
add ( half the coefficient of the x and y terms )² to both sides
x² + 2(- 6)x + 36 + y² + 2(2)y + 4 = 60 + 36 + 4
(x - 6)² + (y + 2)² = 100 ← in standard form
with centre = (6, - 2 ) and r = = 10
Well there are no choices listed so it's going to be hard to say which; we'll write an expression for all of them and then give a few instances.
A parabola with a minimum forms a CUP, concave-up positive, meaning the coefficient a on x² must be positive, a>0.
The general form with vertex (p,q) is
y = a(x-p)² + q
So for us, all our parabolas are of the form
y = a(x- -3)² + 9
y = a(x² + 6x + 9) + 9
y = ax² + 6ax + 9(a+1)
That's the general form for a parabola with vertex (-3,9); a>0 assure the parabola has a minimum at the vertex.
Some instances:
a=1 gives
Answer: y = x²+6x+18
a=4 gives
y = 4x² + 24x + 45
Other positive <em>a</em>s give other possible answers; without the choices it's impossible to know which one they're seeking.
F ( 6 ) = -16·6²+32·6+90= -576 + 192 + 90 = -294
f ( 4 ) = -16· 4³+32·4+90=-256+128+90= -38
The average rate of change: [f(t2)-f(t1)]/ t2-t1=
[-294-(-38)] / (6-4) = -256 : 2 = -128 feet/s
So z
z=onesplace
is the sum of the digits in a dozen (dozen=12 so 1+2=3) ones place=3
3
Answer: X = 57.5
Step-by-step explanation:
3x - 65 + x + 15 = 180
4x - 50 = 180
4x = 230
x = 57.5