Jika diketahui tg a = t,maka nilai sin 2a adalah...

[tex]tg a = t = \frac{t}{1} \\ y = t, x = 1 \\ r = \sqrt{x^{2} + y^{2}} = \sqrt{1 + t^{2}} \\ sin a = \frac{y}{r} =[tex]2. \frac{t}{ \sqrt{1 + t^{2}} }. \frac{1}{ \sqrt{1 + t^{2}} } = ....[/tex]  } \\ cos a = \frac{x}{r} = \frac{1}{ \sqrt{1 + t^{2}}} [/tex]

sin 2a = 2 sin a. cos a

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