Odpowiedź:
z.1
sin²α + cos²α = 1 ⇒ sin² α = 1 - [tex]\frac{25}{49}[/tex] = [tex]\frac{4*6}{49}[/tex]
więc sin α = [tex]\frac{2\sqrt{6} }{7}[/tex]
tg α = sin α : cos α = [tex]\frac{2\sqrt{6} }{7} *\frac{7}{5}[/tex] = [tex]\frac{2\sqrt{6} }{5}[/tex]
z.2
tg α = [tex]\frac{9}{4} = \frac{y}{x}[/tex] więc x = 4 i y = 9
r² = 4² + 9² = 16 + 81 = 97
r = [tex]\sqrt{97}[/tex]
sin α = [tex]\frac{y}{r} = \frac{9}{\sqrt{97} }[/tex] cos = [tex]\frac{x}{r} = \frac{4}{\sqrt{97} }[/tex]
z.3
P = 0,5*5 cm* 8 cm* sin 60° = 20*[tex]\frac{\sqrt{3} }{2}[/tex] cm² = 10 √3 cm²
z.4
P = 3,5* 4√2*sin 45° = 14√2*[tex]\frac{\sqrt{2} }{2}[/tex] = 14
Szczegółowe wyjaśnienie:
