Fill in the blanks:
14+15+12=___
14=1×54×5=520;
15=1×45×4=420;
12=1×102×10=1020
520+420+1020=5+4+1020=1920
{1(sec2θ−cos2θ)+1(cosec2θ−sin2θ)}(sin2θcos2θ)=1−sin2θcos2θ2+sin2θcos2θ
Determine whether the following numbers are in proportion or not:
13,14,16,17