Trig Identities

According to the even/odd trig. identities:  $\cos(-y)=$ 

•  $1$  

•  $\cos(x)$  

•  $\cos(y)$  

• Who knows ... I have missed so many lessons.

Which of these is true because of even symmetry?

• $\cos\left(-40\degree\right)=\cos\left(40\degree\right)$

• $\sin\left(-56\degree\right)=-\sin\left(56\degree\right)$

• $\tan\left(44\degree\right)=\cot\left(46\degree\right)$

• $\tan\left(12\degree\right)=\frac{1}{\cot\left(78\degree\right)}$

 $\cos\left(-\frac{4\pi}{5}\right)=$  
Complete this equation using even symmetry.

•  $\frac{1}{\sec\left(-\frac{4\pi}{5}\right)}$  

•  $\sin\left(-\frac{4\pi}{5}\right)$  

•  $-\cos\left(\frac{4\pi}{5}\right)$  

•  $\cos\left(\frac{4\pi}{5}\right)$  

According to the even/odd trig. identities:  $\csc(-y)=$ 

•  $1$  

•  $-\csc(x)$  

•  $\csc(y)$  

• -1

According to the even/odd trig. identities:  $\sec(-y)=$ 

•  $1$  

•  $-\sec(x)$  

•  $\sec(y)$  

• -1

What does the "co" in cofunction represent?

• common

• complimentary

• complementary

• colinear

 $\cos\left(28\degree\right)=\sin\left(62\degree\right)$  
What identity proves these are equal?

• Pythagorean

• Cofunction

• Reciprocal

• Periodicity

Which of the following is NOT a Pythagorean Identity?

• $\sin^2\left(\theta\right)+\cos^2\left(\theta\right)=1$

• $\tan^2\left(\theta\right)+1=\sec^2\left(\theta\right)$

• $\sec^2\left(\theta\right)+\csc^2\left(\theta\right)=1$

• $1+\cot^2\left(\theta\right)=\csc^2\left(\theta\right)$

 $\cos\left(\frac{\pi}{5}\right)=\frac{1}{\sec\left(\frac{\pi}{5}\right)}$  
What identity proves these are equal?

• Reciprocal

• Quotient

• Cofunction

• Even symmetry

 $\cot\left(341\degree\right)=\frac{\cos\left(341\degree\right)}{\sin\left(341\degree\right)}$  
What identity proves these are equal?

• Reciprocal

• Quotient

• Cofunction

• Periodicity