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DochEvi [55]
3 years ago
8

1. Choose the trig expression equal to the one below 2cos^2 x - 1

Mathematics
1 answer:
Shtirlitz [24]3 years ago
7 0

Answer:

cos(2x) = 2cos²(x)-1

Step-by-step explanation:

We know the trigonometry identity as follows :

cos(2x) = cos²(x) – sin²(x)  ....(1)

Also, sin²(x)+cos²(x) = 1

or

sin²(x) = 1-cos²(x)

Put the value of sin²(x) in equation (1)

cos(2x) = cos²(x) – (1-cos²(x))

= cos²(x) –1+cos²(x)

cos(2x) = 2cos²(x)-1

Hence, 2cos²(x)-1 is equal to cos(2x).

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Answer # 1 and answer #4

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If line XY is a bisector, it divided the line YW in half, therefore making ZY equal to ZW

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