Answer: Choice D
sin^2(x) + 1
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Work Shown:
2sin^2(x) + cos^2(x)
2sin^2(x) + 1 - sin^2(x) .. see note below
[ 2sin^2(x) - sin^2(x) ] + 1
sin^2(x) + 1
note for step 2 above, I used the Pythagorean trig identity (or a slight variation of it) to replace cos^2(x) with 1-sin^2(x).
