11th Class
Mathematics
Sample Paper
Mathematics Olympiad - Sample Paper-13
question_answer
If\[f\left( \frac{-a}{a-1} \right)\], then \[({{a}_{1}}{{b}_{2}}-{{b}_{1}}{{a}_{2}})\,({{b}_{1}}{{c}_{2}}-{{b}_{2}}{{c}_{1}})\]\[={{({{c}_{1}}{{a}_{2}}-{{c}_{2}}{{a}_{1}})}^{2}}.\]\[+\,2ab\,\cos \,(\alpha -\beta )\,\] is equal to