Mathematics - Trigonometric Ratios & Identities Question with Solution | TestHub

$r_1=\frac{\Delta }{s-a},r_2=\frac{\Delta }{s-b},r_3=\frac{\Delta }{s-c}$ substitute this value and take abc common

$$\text{ L.H.S }=\frac{abc}{\Delta }\left[\frac{s-a}{a}+\frac{s-b}{b}+\frac{s-c}{c}\right]=\frac{abc}{\Delta }\left[\sum \frac{s}{a}-3\right]\Rightarrow k=2$$