Simplify: sin(x + pi/2).
Answer and explanation
Correct answer: C. cos(x)
- Step 1: Use the angle addition formula: sin(x + pi/2) = sin(x)cos(pi/2) + cos(x)sin(pi/2).
- Step 2: Since cos(pi/2) = 0 and sin(pi/2) = 1, sin(x)0 + cos(x)1 = cos(x).
Answer
cos(x).
Why not the others: '-cos(x)' is sin(x - pi/2); 'sin(x)' assumes a shift of 2*pi; '-sin(x)' is sin(x + pi).
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