Question

Given, $12\cot A=5$, the value of $\frac{\sin A+\cos A}{\sin A-\cos A}$ is

• A. $7$
• B. $7/17$
• C. $17/7$
• D. $17$

Answer 1

The correct option is C $17/7$

$cotA=\frac{5}{12}=\frac{cosA}{sinA}$

so cos $A=\frac{5}{\sqrt{5^2+{12}^2}}=\frac{5}{13}sinA=\frac{12}{13}$

So $\frac{sinA+cosA}{sinA-cosA}=\frac{12+5}{12-5}=\frac{17}{7}$