Answer:
using the formula
we replace the coordinates
the we calculate
the answer will be square 100 which will give us 10
Answer:
Step-by-step explanation:
The first parabola has vertex (-1, 0) and y-intercept (0, 1).
We plug these values into the given vertex form equation of a parabola:
y - k = a(x - h)^2 becomes
y - 0 = a(x + 1)^2
Next, we subst. the coordinates of the y-intercept (0, 1) into the above, obtaining:
1 = a(0 + 1)^2, and from this we know that a = 1. Thus, the equation of the first parabola is
y = (x + 1)^2
Second parabola: We follow essentially the same approach. Identify the vertex and the two horizontal intercepts. They are:
vertex: (1, 4)
x-intercepts: (-1, 0) and (3, 0)
Subbing these values into y - k = a(x - h)^2, we obtain:
0 - 4 = a(3 - 1)^2, or
-4 = a(2)². This yields a = -1.
Then the desired equation of the parabola is
y - 4 = -(x - 1)^2
Option B:

Solution:
In the given figure
.
If two triangles are similar, then their corresponding sides and angles are equal.
By CPCTC, in
,
– – – – (1)
– – – – (2)
– – – – (3)
– – – – (4)
– – – – (5)
– – – – (6)
Option A: 
By CPCTC proved in equation (2)
.
Therefore
. Option A is false.
Option B: 
By CPCTC proved in equation (1)
.
Therefore Option B is true.
Option C: 
By CPCTC proved in equation (4)
.
Therefore
. Option C is false.
Option D: 
By CPCTC proved in equation (5)
.
Therefore
. Option D is false.
Hence Option B is the correct answer.

Using the given information, we can say the following:
Width (W) = x
Length (L) = (2x - 4)
Area of Rectangle = L × W
Using this, we can formulate an equation for rectangle in question:
x(2x - 4) = 30
Expand and move everything to one side:
2x² - 4x - 30 = 0
Simplify by dividing everything on both sides by 2:
x² - 2x - 15 = 0
Factorise:
(x + 5)(x - 3) = 0
Set each factor equal to 0 and solve for x:
x + 5 = 0
x = -5 (a dimension cannot be negative so this is not the solution we want)
x - 3 = 0
x = 3 (this is the solution)
x = W = 3"
L = 2x - 4
L = 2(3) - 4
L = 2"
So, the length the rectangle is 2" and the width is 3"