Answer: see proof below
<u>Step-by-step explanation:</u>
Given: cos 330 = 
Use the Double-Angle Identity: cos 2A = 2 cos² A - 1

Proof LHS → RHS:
LHS cos 165
Double-Angle: cos (2 · 165) = 2 cos² 165 - 1
⇒ cos 330 = 2 cos² 165 - 1
⇒ 2 cos² 165 = cos 330 + 1
Given: 

Divide by 2: 

Square root: 
Scratchwork: 

Since cos 165 is in the 2nd Quadrant, the sign is NEGATIVE

LHS = RHS 
Answer:
1 1/5 cups of butter
Step-by-step explanation:
4/5=2
=3
4/5 x 3=12/5
12/5 / 2
12/5 x 1/2=1 1/5
I=√-1 and all the steps are there
It is 7-7-77-8-7-7-7777-75a
To prove that <span>AEC≅ AED, we need to write following proofs or statement reasons.
It is given that points C and D are equidistant to point A. Hence,
</span><span>AD ≅ AC
Next, </span><span>CAE ≅ DAE. AE is the common side or the included side.
</span><span>
Then, </span><span>AE ≅ EA by Reflexive Property of Congruence as it is congruent to itself.
Lastly, </span><span>EAD ≅ EAC by Symmetric Property of Congruence as these triangles are mirror image of each other.
</span>
Therefore, we can conclude that AEC≅ AED by SSS or Side-Side-Side. That is when all sides of triangles are congruent then both triangles are deemed to be equal.