Trigonometryhard · Past Paper
If sec A + tan A = x, then find the value of sin A.
A(x^2 - 1) / (x^2 + 1)
B(x^2 + 1) / (x^2 - 1)
C2x / (x^2 + 1)
D2x / (x^2 - 1)
✓ Correct Answer: A — (x^2 - 1) / (x^2 + 1)
sec A - tan A = 1/x. Adding: 2 sec A = x + 1/x. Subtracting: 2 tan A = x - 1/x. sin A = tan A / sec A = (x^2 - 1) / (x^2 + 1).
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