Trigonometryhard · Past Paper

If cosec A + cot A = 3, what is the value of cos A?

A3/5
B4/5
C1/2
D1/3

✓ Correct Answer: B4/5

cosec - cot = 1/3. Adding: 2 cosec = 3 + 1/3 = 10/3, so sin = 3/5. b = sqrt(5^2-3^2) = 4. cos = 4/5.

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