Railroads on the Railways required tracks for the trains to run on them these tracks earlier made up of iron for its heavy duty but soon enough realise that iron was not a very good option for tracks. Meaning drawbacks of using iron for example rusting is it was realised that Steel was a better option in making railroads.
Steel being made out of iron is heavy duty material yet it is not much prone to rusting. Just addition of certain minerals and carbon in iron steel forging is done making it heavy duty material.
The most obvious difference is in the two groups' names. The YAF appears to show much nationalism, while the SDS suggests to us that it is Democratic. The similarity about these two groups are that they both are run by young people, as their names start with "Student" and "Young."
Muhammad's first revelation was according to Islam, was when Gabreil spoke to him in 610 CE. He told him to follow the Quaran, the equivalent to a Bible for christanity
We are asked to simplify cos theta - sec theta / sin theta in terms of sine and cosine. sec theta is the inverse function of cos theta. This results to the expression : (cos theta - 1/ cos theta)/sin theta ( cos^2 theta - 1) / sin thetafrom the trigonometric identity which is cos^2 theta + sin^2 theta = 1;
-sin ^2 theta / sin theta this is equal hence to -sin theta.
