Your answer would be -11 :)
Focus on triangles DFC and DFE:
- They are both right triangles because DF is perpendicular to EC
- DC=DE
- DF is a common side
So, the two triangles are congruent. It follows that CF=FE, and in particular

And since x=3, the length of EF is

The <u>rise</u> is the difference in y-coordinates:
The <u>run</u> is the difference in x-coordinates:
The <u>slope</u> is the quotient of rise over run:
========================
If two points on a line are A(10, −3) and B(12, 9), the rise is <u>12</u>, and the run is <u>2</u>, so the slope of the line is <u>6</u>.
1.
the x value of the vertex in form
ax^2+bx+c=y
is
-b/2a
so
-2x^2+8x-18
x value of vertex is
-8/(2*-2)=-8/-4=2
plug it in to get y value
-2(2)^2+8(2)-18
-2(4)+16-18
-8-2
-10
vertex is at (2,-10)
or you could complete the square to get into y=a(x-h)^2+k, where the vertex is (h,k)
so as follows
y=(-2x^2+8x)-18
y=-2(x^2-4x)-18
y=-2(x^2-4x+4-4)-18
y=-2((x-2)^2-4)-18
y=-2(x-2)^2+8-18
y=-2(x-2)^2-10
vertex is (2,-10)
5.
vertex is the time where the speed is the highest
at about t=10, the speed is at its max
Answer:
r = 3.
Step-by-step explanation:
16 = 10 + √(3r + 27)
√(3r + 27) = 6
Square both sides:
3r + 27 = 36
3r = 36 - 27 = 9
r = 3.
Check the result:
Left side of the equation = 16
Right side = 10 + √(9 + 27)
= 10 + √36 = 16