Answer:
a = 1/2 (1 ±sqrt(47))
Step-by-step explanation:
a^2-a+12=0
We will complete the square
Subtract 12 from each side
a^2-a+12-12=0-12
a^2-a=-12
The coefficient of a = -1
-Divide by 2 and then square it
(-1/2) ^2 = 1/4
Add it to each side
a^2 -a +1/4=-12 +1/4
(a-1/2)^2 = -11 3/4
(a-1/2)^2= -47/4
Take the square root of each side
sqrt((a-1/2)^2) =sqrt(-47/4)
a-1/2 = ±i sqrt(1/4) sqrt(47)
a-1/2= ±i/2 sqrt(47)
Add 1/2 to each side
a-1/2+1/2 = 1/2± i/2 sqrt(47)
a = 1/2± i/2 sqrt(47)
a = 1/2 (1 ±sqrt(47))
Answer:
Option 4, 64 cm^2
Step-by-step explanation:
The polygon in the shape of a star can be made to be easier to find the area of by cutting it into triangle. For all the "point edges" of the star, we can cut them in half from the vertex to create two right-angled triangles at each edge.
The formula of the area of a triangle is bh/2: the height is given as 6cm, the base is 4cm /2 (after you cut it in half) and so is 2 cm. Since the edges can be cut into two, there are 8 right angled triangles at the edges in total.
To find the area of them:
A=8(bh/2)=8(2*6/2)=48 cm^2
However, we are still missing the part at the centre we haven't found the area of, the square. The area of a square is given by the square of the side length(4cm). Thus, A=4*4=16cm^2
Adding the areas of all the edges and the square:
48 + 16 = 64cm^2
Hence, the area of the polygon is 64cm^2
Answer:
The answer is 5.8 times a second
Step-by-step explanation:
Divide 1044 by 180 (The number of seconds in 3 minutes)
