kasihtau jalan nya :)

jawab

(a)
tan (A+B) = (tan A + tanB) / (1 - tan A . tanB)

tan 75 = tan (45+30)
= (tan 45 + tan 30)/ ( 1- tan 45 .tan 30)
= (1 + 1/√3) /( 1 - 1/√3)...}kalikan √3/√3
= (√3  +1) /(√3  -1) ...} kalikan (√3 + 1).(√3 +1)
= (√3 +1)²/(3-1)
= (3 + 1 + 2√3)/(2)
= (4 + 2√3)/(2)
= 2 + √3

(b) tan π/12 = tan (π/3 - π/4)
= (tan π/3  -tan π/4 )/ (1 +  tan π/3. tan π/4)
= (√3  - 1)/( 1 + √3)
= (√3 - 1 )/(√3 + 1)  ...}kalikan (√3 -1)/(√3 -1)
=(√3 -1)²/(3 - 1)
= (3 +1 - 2√3)/(2)
= (4 - 2√3)/(2)
= 2 - √3