The value of (sin10 + sin50) / (sin35 × sin55) is detailed Why is sin10 + sin50 equal to cos20?

The value of (sin10 + sin50) / (sin35 × sin55) is detailed Why is sin10 + sin50 equal to cos20?

sin10 + sin50
= sin(30-20) + sin(30+20)
= 2 * sin30 * cos20
= cos20
sin35 * sin55
= sin35 * cos35
= 1/2 * sin70
= 1/2 * cos20
∴ (sin10 + sin50) / (sin35 * sin55)
= cos20 / (1/2 * cos20)
= 2

(sin10 ° + sin50 °) / sin35 ° sin55 ° value
It is not necessary to use the sum difference product formula to solve other problems

(sin10°+sin50°)/sin35°sin55°=(sin（30°-20°）+sin（30°+20°)）/sin35°sin55°=（sin30°cos20°-cos30°sin20°+sin30°cos20°+cos30°sin20°）/sin35°cos35°=4sin30°cos20°/sin70°=2

sin10+sin50-sin70

sin(60-50)+sin50-sin70
=sin60cos50-cos60sin50+sin50-sin70
=sin(60+50)-sin70
=sin70-sin70=0