Use a Graphing Utility to Select the Correct Graph $y _ { 1 } \text { and } y _ { 2 }$

Multiple Choice

Use a graphing utility to select the correct graph $y _ { 1 } \text { and } y _ { 2 }$ in the same viewing window. Use the graphs to determine whether $y _ { 1 } = y _ { 2 }$ .
Explain your reasoning.
$y _ { 1 } = \cos ( x + 6 ) , y _ { 2 } = \cos x + \cos 6$

A)

No, $y _ { 1 } \neq y _ { 2 }$ because their graphs are different.
B)

No, $y _ { 1 } \neq y _ { 2 }$ because their graphs are Same.
C)

Yes, $y _ { 1 } = y _ { 2 }$ because their graphs are different.

D)

Yes, $y _ { 1 } = y _ { 2 }$ because their graphs are
same.
E)

No, $y _ { 1 } = y _ { 2 }$ because their graphs are
different.