Answer:
1.a=2
2. C x=2 and x=-3
Step-by-step explanation:
The standard form for the quadratic function is
ax^2 +bx+c
so we need to rewrite the function to be in this form
2x^2 -10 = 7x
Subtract 7x from each side
2x^2 -7x-10 = 7x-7x
2x^2 -7x-10 = 0
a =2, b= -7 c=-10
2. The quadratic formula is
-b ± sqrt(b^2 -4ac)
----------------------------
2a
2x^2 + 2x=12
Lest get the equation in proper form
2x^2 + 2x-12 = 12-12
2x^2 +2x-12 =0
a=2 b=2 c=-12
Lets substitute what we know
-2 ± sqrt(2^2 -4(2)(-12))
----------------------------
2(2)
-2 ± sqrt(4+96)
----------------------------
2(2)
-2 ± sqrt(100)
----------------------------
4
-2 ± 10
----------------------------
4
-2 + 10 -2-10
----------- and --------------
4 4
8/4 and -12/4
2 and -3
From the astronaut to the horizon is a tangent line to the curvature of the earth. And from that point on the horizon to the center of the earth is at a right angle to the tangent and is equal to the radius of the earth...so we can say
cosα=r/(r+h) where r is the radius of the earth and h is the height above the surface of the earth...
α=arccos(r/(r+h))
now tanα=d/r where d is the distance from the astronaut to the point on the horizon so:
tan(arccos(r/(r+h))=d/r
d=rtan(arccos(r/(r+h))) and using r≈4000 and h=50 we get:
d=4000tan(arccos(4000/(4050)))
d≈634.42mi
d≈634 mi (to nearest mile)
As likely as not.
EXPLANATION: a coin has 2 sides. (usually heads and tails)
50% chance it is heads
50% chance it is tails
50=50.
So it is just as likely to happen as it is likely to not.
Answer:
6.907
Step-by-step explanation:
