False, you would just divide 20 by -4 to get the answer.
Answer: see proof below
<u>Step-by-step explanation:</u>
Use the Double Angle Identity: sin 2Ф = 2sinФ · cosФ
Use the Sum/Difference Identities:
sin(α + β) = sinα · cosβ + cosα · sinβ
cos(α - β) = cosα · cosβ + sinα · sinβ
Use the Unit circle to evaluate: sin45 = cos45 = √2/2
Use the Double Angle Identities: sin2Ф = 2sinФ · cosФ
Use the Pythagorean Identity: cos²Ф + sin²Ф = 1
<u />
<u>Proof LHS → RHS</u>
LHS: 2sin(45 + 2A) · cos(45 - 2A)
Sum/Difference: 2 (sin45·cos2A + cos45·sin2A) (cos45·cos2A + sin45·sin2A)
Unit Circle: 2[(√2/2)cos2A + (√2/2)sin2A][(√2/2)cos2A +(√2/2)·sin2A)]
Expand: 2[(1/2)cos²2A + cos2A·sin2A + (1/2)sin²2A]
Distribute: cos²2A + 2cos2A·sin2A + sin²2A
Pythagorean Identity: 1 + 2cos2A·sin2A
Double Angle: 1 + sin4A
LHS = RHS: 1 + sin4A = 1 + sin4A 
3/4 divided by 1/3 = 3/4 * 3/1 = 9/4 = 2 1/4 <-------reason
Sun Yi can cut out 2 pieces.
Sun Yi will have 1/4 left.
Answer:
D
Step-by-step explanation:
use the formula for point slope form, since all of your choices are in that form : y-y1=m(x-x1) (m is the slope)
we're given that m=2 and the point is (2,9)
Substitute into the equation
y-9=2(x-2)
That means that the answer is D
Hope this helps!
Answer:
c
Step-by-step explanation: