Answer:
Identity is verified.
Step-by-step explanation:
We have to verify the identity 
To prove any identity we always prove one side(either left hand side or right hand side) of the equation equal to the other side.
In this identity we take the left hand side first

(as we know cos(a+b) = cosa×cosb-sina×sinb)


= - sinx ( Right hand side)
Hence identity is proved.
Answer:
b = 7, c = -44
Step-by-step explanation:
If the quadratic equation has the solutions -11 and 4, the two factors are:

Since when we use the zero factor property we get
x+11=0 ⇒ x= -11
x-4=0 ⇒ x=4
Thus, we have used the zero factor property in reverse to find the factorization of the quadratic equation.
Now we develop the multiplications between parenthesis:

So b is the number that accompanies the x: b = 7
and c is the independent number: c = -44
Answer:
B.
Step-by-step explanation:
Total surface area of the square pyramid
= 4 times the area of one triangle + Area of square

Answer:
i dont speak or type spanish
Step-by-step explanation:
We are given function: y= 
Where, x is the number of hours after 5a.m.
We need to approximates the number of people standing in line to catch a commuter train at 7 a.m.
From 5 a.m. to 7 a.m. total number of hours = 7-5 = 2 hours.
So, we need to plug x=2 in the given function.
Plugging x=2 in
, we get

Let us simplify it now.
2^2= 4.
Therefore,

= -20.524 + 63.642 - 3.333.
= 39.785 or 40 approximately.
Therefore, the number of people in line at 7 a.m. is approximately 40 people.
Option D.40 is correct option.