Answer:
The work is in the explanation.
Step-by-step explanation:
The sine addition identity is:
.
The sine difference identity is:
.
The cosine addition identity is:
.
The cosine difference identity is:
.
We need to find a way to put some or all of these together to get:
.
So I do notice on the right hand side the 
and the 
.
Let's start there then.
There is a plus sign in between them so let's add those together:
![=[\sin(a+b)]+[\sin(a-b)]](https://tex.z-dn.net/?f=%3D%5B%5Csin%28a%2Bb%29%5D%2B%5B%5Csin%28a-b%29%5D)
![=[\sin(a)\cos(b)+\cos(a)\sin(b)]+[\sin(a)\cos(b)-\cos(a)\sin(b)]](https://tex.z-dn.net/?f=%3D%5B%5Csin%28a%29%5Ccos%28b%29%2B%5Ccos%28a%29%5Csin%28b%29%5D%2B%5B%5Csin%28a%29%5Ccos%28b%29-%5Ccos%28a%29%5Csin%28b%29%5D)
There are two pairs of like terms. I will gather them together so you can see it more clearly:
![=[\sin(a)\cos(b)+\sin(a)\cos(b)]+[\cos(a)\sin(b)-\cos(a)\sin(b)]](https://tex.z-dn.net/?f=%3D%5B%5Csin%28a%29%5Ccos%28b%29%2B%5Csin%28a%29%5Ccos%28b%29%5D%2B%5B%5Ccos%28a%29%5Csin%28b%29-%5Ccos%28a%29%5Csin%28b%29%5D)
So this implies:
Divide both sides by 2:
By the symmetric property we can write:
The numbers are (-8, 3) or (3, -8).
Step-by-step explanation:
- Step 1: Given the product of the numbers are -24 and their sum are -5. Let the numbers be a and b. Form equations out of these details.
⇒ a + b = -5 ⇒ b = -5 - a
⇒ a × b = -24 -------- (1)
- Step 2: Substitute the value of b in eq(1)
⇒ a × (-5 - a) = - 24
⇒ -5a - a² = -24
⇒ a² + 5a - 24 = 0
- Step 3: Solve the quadratic equation for a.
a = (-5 ± √25 - 4 × 1 × -24)/2
= (-5 ± √121)/2
= - 16/2, 6/2 = -8 or 3
- Step 4: For each value of a, find b.
When a = -8, b = -5 +8 = 3
When a = 3, b = -5 - 3 = -8.
Answer:
(E) 90°
Step-by-step explanation:
The diagonals of a parallelogram are equal in length if and only if the parallelogram is a rectangle.
Any angle of a rectangle is 90°.
_____
Adjacent angles of a parallelogram are supplementary. If the diagonals are the same length, the triangles formed by either diagonal are congruent with the triangles formed by the other diagonal. This means adjacent angles are congruent. Congruent supplementary angles are 90°.
A probability of 0.075 corresponds to a z-score of about
, i.e.
The expression can be solved by expanding the bracket and multiplying out the terms
Therefore, the expression can be simplified as;
Alternatively, using the theorem of difference of two squares, which is
Hence,
