Answer:
Therefore the correct assembling is
3.∠DAC ≅ ∠BCA 3. Alternate interior Angles are Equal as AD || BC.
Step-by-step explanation:
Given:
AD ≅ BC and AD || BC
To Prove:
ABCD is a Parallelogram
Proof:
Alternate Interior Angles Theorem :
"When two parallel lines are cut by a transversal , the resulting alternate interior angles are congruent.
Here AD || BC and the transversal is AC
Statement Reasons
1. AD ≅ BC . 1. Given
2. AD || BC 2. Given
3.∠DAC ≅ ∠BCA 3. Alternate interior Angles are Equal as AD || BC.
Therefore the correct assembling is
3.∠DAC ≅ ∠BCA 3. Alternate interior Angles are Equal as AD || BC.
Answer:
9pr = 2q^2
Step-by-step explanation:
28.
px^2 + qx + r = 0
If one root is A then the other root is 2A
We have A + 2A = -q/p and A*2A = r/p
So 3A = -q/p so A = -q/3p and A^2 = r/2p so A = √ (r / 2p)
Equating these 2 equations:-
-q/3p = √(r / 2p)
q^2 / 9p^2 = r / 2p
9p^2r = 2pq^2
9pr = 2q^2 (answer)
Answer:
87.31
Step-by-step explanation:
STAY SAVAGE
Recall the sum identity for cosine:
cos(a + b) = cos(a) cos(b) - sin(a) sin(b)
so that
cos(a + b) = 12/13 cos(a) - 8/17 sin(b)
Since both a and b terminate in the first quadrant, we know that both cos(a) and sin(b) are positive. Then using the Pythagorean identity,
cos²(a) + sin²(a) = 1 ⇒ cos(a) = √(1 - sin²(a)) = 15/17
cos²(b) + sin²(b) = 1 ⇒ sin(b) = √(1 - cos²(b)) = 5/13
Then
cos(a + b) = 12/13 • 15/17 - 8/17 • 5/13 = 140/221
