SOLUTION: What is the EXACT answer of cot(22.5)?

Algebra ->  Trigonometry-basics -> SOLUTION: What is the EXACT answer of cot(22.5)?      Log On


   

Question 535684: What is the EXACT answer of cot(22.5)?
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
What is the EXACT answer of cot(22.5)
use half angle formula for tan
tan(22.5º)=tan (45º/2)=(sin 45)/(1+cos(45))
tan(22.5º)=(√2/2)/(1+√2/2)=(√2/2)/(2+√2)/2=√2/(2+√2)
cot(22.5º)=1/tan(22.5º)=(2+√2)/√2=(2√2+2)/2=√2+1
cot(22.5º)=√2+1