Question

me ajudem por favor​

Answer 1

1

$\tan( \alpha ) = \frac{ \sin( \alpha ) }{ \cos( \alpha ) } \\ \tan( \alpha ) \: = \frac{c.o.}{c.a.} \\ \sin( \alpha ) \: = \frac{c.o.}{h} \\ \cos( \alpha ) = \frac{c.a.}{h} \\ \frac{ \sin( \alpha ) }{ \cos( \alpha ) } \frac{ \frac{c.o.}{h} }{ \frac{c.a.}{h} } = \frac{c.o.}{h} \times \frac{h}{c.a.} = \frac{c.o.}{c.a.} = \tan( \alpha )$

2

sen 30 = oposto/hipotenusa = 0,5

x/4000 = 0,5

x = 4000 × 0,5 = 2000m

3

$3 {x}^{2} - 5x + 2 = 0 \\ x1 = \frac{5 + \sqrt{ {( - 5)}^{2} - 4 \times 2 \times 3 } }{6} \\ x1 = \frac{5 + \sqrt{25 - 24} }{2 \times 3} = \frac{6}{6} = 1 \\ x2 = \frac{5 - \sqrt{ {( - 5)}^{2} - 4 \times 2 \times 3}}{2 \times 3} \\ x2 = \frac{5 - \sqrt{25 - 24} }{6} = \frac{4}{6} = \frac{2}{3}$