Question

URGENTEEEE!!!!!!

Em cada caso calcule o valor de x

Resolver o b

Answer 1

Resposta:

x = 2,351 m

(aproximadamente)

Explicação passo-a-passo:

.

b) triângulo retângulo

.

Sen 72° = √5 m / x

O,951 = √5 m / x

x = √5 m / 0,951 .. (√5 = 2,236)

x = 2,236 m / 0,951

x = 2,351 m

.

(Espero ter colaborado)

Answer 2

Explicação passo-a-passo:

Temos que:

$\sf sen~72^{\circ}=\dfrac{cateto~oposto}{hipotenusa}$

$\sf \dfrac{\sqrt{10+2\sqrt{5}}}{4}=\dfrac{\sqrt{5}}{x}$

$\sf x\cdot\dfrac{\sqrt{10+2\sqrt{5}}}{4}=\sqrt{5}$

$\sf x\cdot\sqrt{10+2\sqrt{5}}=4\sqrt{5}$

$\sf x\cdot\sqrt{10+2\sqrt{5}}\cdot\sqrt{10+2\sqrt{5}}=4\sqrt{5}\cdot\sqrt{10+2\sqrt{5}}$

$\sf x\cdot(10+2\sqrt{5})=4\sqrt{50+10\sqrt{5}}$

$\sf x\cdot(10+2\sqrt{5})\cdot(10-2\sqrt{5})=4\sqrt{50+10\sqrt{5}}\cdot(10-2\sqrt{5})$

$\sf x\cdot[10^2-(2\sqrt{5})^2]=40\sqrt{50+10\sqrt{5}}-8\sqrt{250+50\sqrt{5}}$

$\sf x\cdot[100-20]=40\sqrt{50+10\sqrt{5}}-8\sqrt{250+50\sqrt{5}}$

$\sf x\cdot80=40\sqrt{50+10\sqrt{5}}-8\sqrt{250+50\sqrt{5}}$

$\sf x=\dfrac{40\sqrt{50+10\sqrt{5}}-8\sqrt{250+50\sqrt{5}}}{80}$

$\sf x=\dfrac{5\sqrt{50+10\sqrt{5}}-\sqrt{250+50\sqrt{5}}}{10}$

$\sf x=\dfrac{5\sqrt{50+10\sqrt{5}}-\sqrt{5\cdot(50+10\sqrt{5})}}{10}$

$\sf x=\dfrac{5\sqrt{50+10\sqrt{5}}-\sqrt{5}\cdot\sqrt{50+10\sqrt{5}}}{10}$

$\sf \red{x=\dfrac{(5-\sqrt{5})\cdot\sqrt{50+10\sqrt{5}}}{10}~m}$