الموقع التخصصى فى الرياضيات للثانوية العامة - عرض مشاركة واحدة

مهيب الأرنؤوطى · #3 02-15-2011, 03:01 AM

$\left ( 11 \right )\, \, if\, \, \frac{cos\left ( B \right )}{a}=\frac{cos\left ( A \right )}{b}\, \, in\, \, the\, \, triangle\, \, abc,\, \, prove\, \, that\, this\, \, triangle\, \, is:$
$either\, \, right\, \, angled\, \, triangle\, \, or\, \, isosceles\, \, triangle$

$\left ( 12 \right )\, \, prove\, \, that:\, \, sinA+sinB+sinC=\frac{4P\bigtriangleup }{a.b.c}$
$such\, \, that:\, \, P\, \, is\, \, the\, \, half\, \, of\, \, its\, \, peremiter\, \, and\, \, \bigtriangleup is\, \, its\, \, surface\, \, area$

$\left ( 13 \right )\, \, in\, \, the\, \, previous\, \, problem\, \, prove\, \, that:$
$\frac{1}{\left ( c \right )sinA}=\frac{1}{\left ( a \right )sinB}=\frac{1}{\left ( b \right )sinC}$

$\left ( 14 \right )\, without\, \, using\, \, calculator,\, prove\, \, that:$
$\left ( sin5+cons5 \right )\left ( sin40+cos50 \right )=\sqrt{2}cos10$

$\left ( 15 \right )\, \, without\, \, calculator\, \, prove\, \, that:$
$tan75=1+tan30+tan30.tan75$