Question

Me ajudem por favor?????

Answer 1

Resposta:

a) cos(x)= 3/5 b)A= $5(\sqrt{3} +1 )$

Explicação passo-a-passo:

a) sen(x)= 4/5 ou seja

cos^2(x) + 16/25= 1

cos^2(x) = 9/25

cos(x)= 3/5

b) cos(60)= 1/2  sen(60)= $\frac{\sqrt{3} }{2}$    tg(60)=$\sqrt{3}$ cos(180)= 1 sen(120)=

$\frac{\frac{3\sqrt{3} }{2}+\frac{5}{2} - \sqrt{3} }{1+\frac{\sqrt{3} }{2} }$

$\frac{\frac{3\sqrt{3}+ 5+ 2\sqrt{3} }{2} }{\frac{2+\sqrt{3} }{2} }$

$\frac{5\sqrt{3}+ 5 }{2+\sqrt{3} }$

$\frac{(5\sqrt{3} + 5) (2-\sqrt{3}) }{4-3}$

$10\sqrt{3} +10-15-5\sqrt{3}$

$5\sqrt{3} - 5$

$5(\sqrt{3} +1 )$