(126)ěA+B-C= 180Â°elit,al)tan).tan-(a) 0 (b) 1 (c) 2 (d) 32

1.	(126)ěA+B-C= 180Â°elit,al)tan).tan-(a) 0 (b) 1 (c) 2 (d) 32
Answer» A+B+C = piso A/2 + B/2 + C/2 = pi/2 or A/2 + B/2 = (pi/2- C/2)take tan of both sides tan (A/2 + B/2) = tan (pi/2-C/2) = cot C/2 = 1/ tan C/2 or (tan A/2 + tan B/2)/(1- Tan A/2 tan B/2) = 1/tan C/2 or tan C/2 tan A/2 + tan C/2 tan B/2 = 1 - tan A/2 tan B/2or tan A/2 tan B/2 + tan B/2 tan C/2 + tan A/2 tan C/2 = 1proved

Answer»

A+B+C = piso A/2 + B/2 + C/2 = pi/2

or A/2 + B/2 = (pi/2- C/2)take tan of both sides

tan (A/2 + B/2) = tan (pi/2-C/2) = cot C/2 = 1/ tan C/2

or (tan A/2 + tan B/2)/(1- Tan A/2 tan B/2) = 1/tan C/2

or tan C/2 tan A/2 + tan C/2 tan B/2 = 1 - tan A/2 tan B/2or tan A/2 tan B/2 + tan B/2 tan C/2 + tan A/2 tan C/2 = 1proved

Discussion