tentukan nilai sin 2 beta,cos 2beta dan tan 2beta menggunakan rumus trigonometri sudut rangkap jika di ketahui : B. tan beta=-1/5 di kuadran II

tan ß = -1/5
tan = y/x
r=√x²+y²
r=√1+25
r=√26
sin = y/r = 1/√26
cos = x/r = -5/√26
(kuadran2 hanya sin (+))
sin2ß= 2sinßcosß
sin2ß=2(1/√26)(5/√26) = 10/26 = 5/13
cos2ß=cos²ß-sin²ß
cos2ß=(5/√26)²-(1/√26)² = 25/26-1/26
cos2ß=24/26 = 12/13
tan2ß=2tanß/1-tan²ß
tan2ß=2(-1/5)/1-(-1/5)²
tan2ß=(-2/5)/25+1/25
tan2ß=(-2/5) / 26/25 = -2.25/26.5
tan2ß=-2.5/26= -10/26 = -5/13