\( \definecolor{colordef}{RGB}{249,49,84} \definecolor{colorprop}{RGB}{18,102,241} \)
Below is the graph of the function \( y = \cos(x) \), for \( 0 \leq x \leq 4\pi \).
  1. Find the \( y \)-intercept of the graph.
  2. Use the graph to determine the values of \( x \) in the interval \( 0 \leq x \leq 4\pi \) such that \( \cos(x) = 0 \) :
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