jika sin A= 3/5 dan sudut A dikuadran 2 maka nilai sin 2a adlah

[tex] \sin(a) = \frac{y}{r} = \frac{3}{5} \\ y = 3 \: \: r = 5 \\ {r}^{2} = { x}^{2} + {y}^{2} \\ {x}^{2} = {r}^{2} - {y}^{2} \\ {x}^{2} = {5}^{2} - {3}^{2} \\ {x}^{2} = 25 - 9 \\ {x}^{2} = 16 \\ x = \sqrt{16} \\ x = 4[/tex]
Selanjutnya cari nilai cos A
[tex] \cos(a) = \frac{x}{r} = \frac{4}{5} [/tex]
Maka
[tex] \sin(2a) = 2 \sin(a) \cos(a) \\ = 2. \frac{3}{5} . \frac{4}{5} \\ = \frac{24}{25} [/tex]
Semoga dapat dipahami