Question 209389
cos (x) = 0 when x = 90 and when x = 270 degrees.
cos (2x) = 0 when 2x = 90 and when 2x = 270 degrees.
2x = 90 when x = 45
2x = 270 when x = 135
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i believe your answers are:
x = 45
x = 135
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