Question 488194
4sec(180)-2sin^(2)(270)
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Using your suggestion, which is a good one.
4(1/cos180)-2sin^2(270)
sin 270º=-1
sin^2(270)=1
2sin^2(270)=2
..
cos 180º=-1
1/cos180=-1
4(1/cos180)=-4
..
4(1/cos180)-2sin^2(270)=-4-2=-6