New Enroll in RBI Grade B New Batch - Starts on May 21

    Question

    If sin θ + cos θ = 1.2, find the value of sin θ. cos

    θ.
    A 0.22 Correct Answer Incorrect Answer
    B 1.20 Correct Answer Incorrect Answer
    C 1.44 Correct Answer Incorrect Answer
    D 1.50 Correct Answer Incorrect Answer

    Solution

    We know: sin² θ + cos² θ = 1 (Pythagoras identity). Given: sin θ + cos θ = 1.2. Let sin θ = x and cos θ = y. Then: x + y = 1.2, and x² + y² = ? Using the identity: (x + y)² = x² + y² + 2xy. 1.2² = x² + y² + 2xy. 1.44 = x² + y² + 2xy. From the Pythagoras identity: x² + y² = 1. Substitute into the equation: 1.44 = 1 + 2xy. 2xy = 1.44 - 1 = 0.44. xy = 0.44/2 = 0.22

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