5.4 Sum and Difference Identities

Multiple Choice

Find the value of( You can use calculator)?

• Cos(45-30) = $$\frac{\sqrt[]{6}+\sqrt[]{2}}{4}$$  

• Cos(45+30) = $$\frac{\sqrt[]{6}-\sqrt[]{2}}{4}$$

Multiple Choice

Find the value of( You can use calculator)?

• Sin( $$\frac{\pi}{4}-\frac{\pi}{6}$$  ) = $$\frac{\sqrt[]{6}-\sqrt[]{2}}{4}$$  

• Sin $$\left(\frac{\pi}{4}+\frac{\pi}{6}\right)$$ = $$\frac{\sqrt[]{6}+\sqrt[]{2}}{4}$$

Multiple Choice

Find the value of( You can use calculator)?

• Cos( $$\frac{7\pi}{8}+\frac{5\pi}{24}$$  ) = $$Cos\left(\frac{13\pi}{12}\right)=-\frac{\sqrt[]{6}+\sqrt[]{2}}{4}$$  

• Cos $$\left(\frac{7\pi}{8}-\frac{5\pi}{24}\right)$$ = $$Cos\left(\frac{2\pi}{3}\right)=-\frac{1}{2}$$

Multiple Choice

Simplify?

• $$\ \ \tan\left(6x-7x\right)=\tan\left(-x\right)=-\tan x$$ $$.$$  

• $$\ \ \tan\left(6x+7x\right)=\tan\left(13x\right)$$  

Multiple Choice

Simplify?

• $$Cos\left(\frac{\pi}{2}-\frac{\pi}{6}\right)=\sin\left(\frac{\pi}{6}\right)$$ $$.$$  

• $$\ Cos\left(\frac{\pi}{2}+\frac{\pi}{6}\right)=Sin\left(\frac{\pi}{6}\right)$$  

Multiple Choice

Simplify?

• $$\frac{1}{Cos\left(\frac{\pi}{2}-\frac{\pi}{6}\right)}=\frac{1}{Sin\left(\frac{\pi}{6}\right)}$$   

• $$\frac{1}{Sin\left(\frac{\pi}{2}-\frac{\pi}{6}\right)}=\frac{1}{Cos\left(\frac{\pi}{6}\right)}$$   

Multiple Choice

Simplify?

• $$Cos\left(360\degree-30\degree\right)=Cos\left(30\degree\right)$$    

•   $$Cos\left(360\degree+30\degree\right)=Cos\left(30\right)$$  

Multiple Choice

Simplify?

• $$Sin\left(\frac{\pi}{2}+\frac{\pi}{6}\right)=Cos\left(\frac{\pi}{6}\right)$$    

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Open Ended

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