Question

@Michele_Laino

Answer 1

applying the distrinutive property of multiplication over addition, we can write the se steps:
\[\Large \begin{gathered}
{\left( {\cos \theta } \right)^2}\left\{ {1 + {{\left( {\tan \theta } \right)}^2}} \right\} = \hfill \\
\hfill \\
= {\left( {\cos \theta } \right)^2} + {\left( {\cos \theta } \right)^2}{\left( {\tan \theta } \right)^2} = \hfill \\
\hfill \\
= {\left( {\cos \theta } \right)^2} + {\left( {\cos \theta } \right)^2}\frac{{{{\left( {\sin \theta } \right)}^2}}}{{{{\left( {\cos \theta } \right)}^2}}} \hfill \\
\end{gathered} \]

Answer 2

please continue

Answer 3

-1 ?

Answer 4

hint: