9514 1404 393
Answer:
see attached
Step-by-step explanation:
It isn't clear what is supposed to go in the various blanks. We have elected to identify the corresponding congruent parts, and name the congruent triangles. The postulate supporting the conclusion is also shown.
In most cases, corresponding parts are marked congruent. The exception is the vertical angles in figure 22.
Answer:
a) 
b)

c)

d)
cos 330° = 1- 2 sin² (165°)
Step-by-step explanation:
<u><em>Step(i):-</em></u>
By using trigonometry formulas
a)
cos2∝ = 2 cos² ∝-1
cos∝ = 2 cos² ∝/2 -1
1+ cos∝ = 2 cos² ∝/2

b)
cos2∝ = 1- 2 sin² ∝
cos∝ = 1- 2 sin² ∝/2

<u><em>Step(i):-</em></u>
Given

we know that trigonometry formulas

1- cos∝ = 2 sin² ∝/2
Given

put ∝ = 315

multiply with ' 2 sin (∝/2) both numerator and denominator

Apply formulas

1- cos∝ = 2 sin² ∝/2
now we get

b)

put ∝ = 330° above formula



c )

put ∝ = 315° above formula


d)
cos∝ = 1- 2 sin² ∝/2
put ∝ = 330°

cos 330° = 1- 2 sin² (165°)
Answer:
d
Step-by-step explanation:
i did this one