231,595 views
18 votes
18 votes
Use a difference identity to find the exact value of tan 15.

User Bogdan Goie
by
2.8k points

2 Answers

15 votes
15 votes
X minus positive three minus -2 equals 7-15
User Ravi Ram
by
2.4k points
19 votes
19 votes

Answer:


2-√(3)

Explanation:


tan15 = tan(45 - 30)=(tan(45)-tan(30))/(1+tan(45)tan(30))\\\\=(1-(1)/(√(3)))/(1+(1)/(√(3)))\\\\\\=(√(3)-1)/(√(3)+1)\\\\\\


=((√(3)-1)^2)/(3-1)\\=(3+1-2√(3))/(2)\\=2-√(3)

User Jyotman Singh
by
3.3k points