Section 5.1
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Question 20
cos(pi/2 - x)sex x
I know that pi/2 = 90 degrees.
Cos (90° – x) = Sin x.
We now have sin x• sec x.
I also know that sec x = 1/ sin x.
From this we get sin x • 1/sin x.
sin x • (1/sin x) = sin x/sin x = 1.
Answer: 1
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