Cofunction identities

Lessons

• Introduction
  What are cofunction identities?
  • Relationships between trigonometric functions and their cofunctions

---

• 1.
  Write the following in terms of its cofunction:
  
  $\blacksquare$ $\sin(23)$
  $\blacksquare$ $\cos(47)$
  $\blacksquare$ $\tan(\frac{\pi}{6})$
  $\blacksquare$ $\csc(\frac{\pi}{6})$
  

---

• 2.
  Solve for $x$
  a)

  $\sin(x-\frac{\pi}{4})=\cos(\frac{\pi}{12}+3x)$
  
  
  b)

  $\cot(8^{\circ}+x)=\tan(4x-3^{\circ})$
  
  
  c)

  $\csc(3x+\frac{\pi}{5})=\sec(2x-\frac{\pi}{10})$
  
  

---