engineering mathematics MCQ #5546

What is the value of cos(A + B) + cos(A - B)?

engineering mathematics MCQ #5546

  1. Question 1

    Q1. What is the value of cos(A + B) + cos(A - B)?

    • A) 2 cos(A) cos(B)
    • B) 2 sin(A) sin(B)
    • C) 2 cos(A) sin(B)
    • D) 2 sin(A) cos(B)

    Answer: 2 cos(A) cos(B)

    Explanation: Using sum and difference formulas, cos(A + B) + cos(A - B) = cos(A)cos(B) - sin(A)sin(B) + cos(A)cos(B) + sin(A)sin(B) = 2 cos(A) cos(B).