2019 · Q31
What is the value of log₁₀(cos θ) + log₁₀(sin θ) + log₁₀(tan θ) + log₁₀(cot θ) + log₁₀(sec θ) + log₁₀(cosec θ)?
Elementary MathematicsTrigonometry
- A-1
- B0
- C0.5
- D1
Explanation
The sum equals log10 of the product cos.sin.tan.cot.sec.cosec. Since tan.cot = 1 and sec = 1/cos, cosec = 1/sin, the product is 1, and log10(1) = 0.