trigo, question 10, grade 10

04/12/2016 Grade 10 66

10) Calculate without any use of a calculator:

\begin{array}{l}\bullet5{\sin^2}{15^0}+5{\sin^2}{75^0}\\\bullet{\sin^2}{10^0}+{\sin^2}{80^0}+2{\cos ^2}{40^0}+2{\cos^2}{50^0}\\\bullet2{\sin^2}{50^0}-3{\cos^2}{70^0}+2{\sin^2}{40^0}-3{\cos^2}{20^0}\\\bullet{\sin^2}{85^0}+{\cos^2}{95^0}+{\cos^2}\frac{\pi}{6}\end{array}