Question

Salut, am nevoie de putin ajutor cu urmatoarea ecuatie, am nevoie ca sa fie redusa la o forma mai simpla si cel putin rezolvata, va rog foarte mult!

Answer 1

Răspuns:

$\sqrt{3}$

Explicație pas cu pas:

$\frac{2cos40-cos20}{sin20} =>\frac{cos40+(cos40-cos20)} {sin20} =\frac{cos40-2sin(\frac{40-20}{2} sin(\frac{40-20}{2} }{sin20} =>$

$\frac{cos40-2sin30sin10}{sin20} =\frac{cos40-2*\frac{1}{2} sin10}{sin20} =\frac{cos40-sin10}{sin20} =>\frac{cos(90-50)-sin10}{sin20} =\frac{sin50-sin10}{sin20} =\frac{2cos(\frac{50+10)}{2} sin(\frac{50-10)}{2} }{sin20} =\frac{2cos30sin20}{sin20} =2cos30=>2*\frac{\sqrt{3} }{2} =\frac{\sqrt{3} }{1}=\sqrt{3}$