Boleh minta tolong ….., bantuin yaaa

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Boleh minta tolong …..
bantuin yaaa​

3)

 \tan( \alpha +   \beta )  =  \frac{ \tan( \alpha )  +  \tan( \beta ) }{1 -  \tan( \alpha ) \tan( \beta )  }  \\  =  \frac{ \frac{1}{2}  +  \frac{1}{3} }{1 -  \frac{1}{2}( \frac{1}{3} ) }  \\  =  \frac{ \frac{3 + 2}{6} }{ \frac{6 - 1}{6} }  \\  =  \frac{ \frac{5}{6} }{ \frac{5}{6} }  =  \frac{5}{6}  \times  \frac{6}{5}  = 1

4a)

 \sin(45 +  \alpha )  -  \sin(45 -  \alpha )  \\  = ( \sin(45)  \cos( \alpha )  +  \sin( \alpha )  \cos(45) ) - ( \sin(45)  \cos( \alpha )  -  \cos(45)  \sin( \alpha ) ) \\  =  \sin( \alpha )  \cos(45)  +  \sin( \alpha )  \cos(45)  \\  = 2 \sin( \alpha )  \cos(45)  \\  = 2 \sin( \alpha ) ( \frac{1}{2}  \sqrt{2} ) \\  =  \sqrt{2}  \sin( \alpha )

terbukti

b)

 \sin(150 +  \alpha )  +  \sin(30 +  \alpha )  \\  =  (\sin(150)  \cos( \alpha )  +  \cos( 150 )  \sin( \alpha ) ) + ( \sin(30)  \cos( \alpha )  +  \sin( \alpha )  \cos(30) )

dimana

sin 30 = sin 150

cos 150 = -cos 30

 =   (\sin(30)  \cos( \alpha )   -  \cos( 30 )  \sin( \alpha ) ) + ( \sin(30)  \cos( \alpha )  +  \sin( \alpha )  \cos(30) )  \\  = 2 \sin(30)  \cos( \alpha )  \\  = 2( \frac{1}{2} ) \cos( \alpha )  \\  =  \cos( \alpha )

terbukti

5)

 \sin(c)  =  \frac{y}{r}  =  \frac{3}{5}

x =  \sqrt{ {5}^{2} -  {3}^{2}  }  \\  =  \sqrt{25 - 9}  \\  =  \sqrt{16}  = 4

maka

 \tan(c)  =  \frac{y}{x}  =  \frac{3}{4}

a)

jumlah sudut segitiga = 180

a+b+c = 180

 \tan(a + b)  =  \tan(180 - c)  \\  =  -  \tan(c)  \\  =  -  \frac{3}{4}

b)

 \tan(a + b)  =  \frac{ \tan(a) +  \tan(b)  }{1 -  \tan(a) \tan(b)  }  \\   \tan(a)  +  \tan(b)  =  \tan(a + b) (1 -  \tan(a)  \tan(b) ) \\  =  -  \frac{3}{4} (1 - 5) \\  =  -  \frac{3}{4} ( - 4) \\  = 3

maaf cuma bantu itu ja

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