Write the Following as an Algebraic Expression in U, U $\cos ( \arctan \mathrm { u } )$

question 312

Multiple Choice

Write the following as an algebraic expression in u, u > 0.
- $\cos ( \arctan \mathrm { u } )$

• A) \(\frac { \sqrt { u ^ { 2 } + 1 } } { u ^ { 2 } + 1 }\)
• B) \(u \sqrt { u ^ { 2 } + 1 }\)
• C) \(\frac { u \sqrt { u ^ { 2 } + 1 } } { u ^ { 2 } + 1 }\)
• D) \(\frac { \sqrt { u ^ { 2 } - 1 } } { u ^ { 2 } - 1 }\)