Question 440920
Find the exact value of tan 345 
Use adddition formula for tan
tan(345)=tan(300+45)=(tan300+tan45)/(1-tan300*tan45)
Reference angle for tan 300  is 60 deg in quadrant IV where tan is negative
tan300=-√3
tan45=1
tan 345=(-√3+1)/(1+√3*1)=(1-√3)/(1+√3) 
=(1-√3)/(1+√3)*(1-√3)/(1-√3)=(1-√3)^2/1-3=(1-2√3+3)/2=(4-2√3)/2=2-√3
ans: 
tan345=2-√3