Question

C
If A+B+C = 180° then cot(A÷2) + cot(B÷2) + cot(C÷2)​

Answer 1

Step-by-step explanation:

ttygrrddfagatssgsydysdydy

Answer 2

Answer:

cotA/2 + cotB/2 + cotC/2=cotA/2 cotB/2 cotC/2

Step-by-step explanation:

=> A + B + C = 180°

=> A/2 + B/2 + C/2 =90°

=> A/2 + B/2 = 90 - C/2

=> cot(A/2 + B/2) = cot(90 - C/2)

=> cot(A/2)cot(B/2) - 1/cot(B/2) + cot(A/2) = tanC/2

=> cot(A/2)cot(B/2) - 1/cot(B/2) +cot(A/2) = 1/cotC/2

=> cotA/2 cotB/2 cotC/2 - cotC/2 = cotB/2 + cotA/2

=> cotA/2 cotB/2 cotC/2 = cotA/2 + cotB/2 + cotC/2

=> cotA/2 + cotB/2 + cotC/2=cotA/2 cotB/2 cotC/2