tan 195 derajat = .... +cara

jawab

tan195 = tan (180 +15) = tan 15
tan 15 = tan(45 -30)
=  (tan 45 - tan 30)/ (1+ tan45. tan30)
= (1 - 1/√3) / (1 + 1/√3)
= (√3 - 1)/ (√3 + 1)
= (√3 -1)² /(3 - 1)
= (4  - 2√3)/(2)
= 2 - √3
tan 195 = 2 - √3