Question

In Traiangle ABC if b2+c2=3a2. Then cotB+cotC-cotA equals to
1. 1
2. ab/4 delta
3. 0
4. ac/4 delta
Ans and explanation

Answer 1

Dear Student,
a2 + c2 - b2 / 4∆ = cot B
Same as Cot A and Cot C
Now putting the values we get
0