Answer:
DK = 9
Step-by-step explanation:
In triangle AMD,
h² = p² + b²
or, h² = 6² + 4²
or, h²= 36 + 16
so, h² = 52
so, AM² = 52
Take x as reference angle,
cos²x = 16/52
Now,
In triangle, AMK,
Taking x as reference angle,
cos²x = b²/h²
cos²x = AM²/MK²
or, cos²x = 52/MK²
Now,
cos²x = 16/52 = 52/MK²
or,
16/52 = 52/MK²
or, 16MK² = 2704
or, MK² = 2704/16
or, MK² = 169
so, MK = 13
Now,
DK = MK - MD
or, DK = 13 - 4
so, DK = 9
Answer:
B
Step-by-step explanation:
9514 1404 393
Answer:
-0.16
Step-by-step explanation:
The 'a' value can be found by looking at the difference between the y-value of a point 1 unit from the vertex, and the y-value of the vertex.
Here, that is a negative fraction of a unit. If we assume the value is a rational number that can be accurately determined from this graph, then we can find it by looking for a point where the graph crosses a grid intersection. It looks like such grid points are (-7, 0) and (3, 0). The vertex is apparently (-2, 4), so the vertex form of the equation is ...
y = a(x +2)^2 +4
Using the point (3, 0), we have ...
0 = a(3 +2)^2 +4 . . . . . fill in the values of x and y
-4 = 25a . . . . . . . . . . subtract 4; next, divide by 25
a = -4/25 = -0.16