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"Prove that cos 20° / sin 70° = 1. A) 1 B) 0 C) -1 D) 2"

"Prove that cos 20° / sin 70° = 1. A) 1 B) 0 C) -1 D) 2"
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3 votes
"Prove that cos 20° / sin 70° = 1.
A) 1
B) 0
C) -1
D) 2"

User Jonathan Meguira
by
7.9k points

1 Answer

6 votes

Explanation:


( \cos(20) )/( \sin(70) ) = 1

Using the cofunction identify,


\sin( \alpha ) = \cos(90 - \alpha )


\sin(70) = \cos(90 - 70) = \cos(20)

So


( \sin(70) )/( \sin(70) ) = 1


1 = 1

A

User Joe Sleiman
by
7.8k points
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