Question

If triangle ABC is right angled at C. Find the value of Cot(A+B).

Answer 1

SOLUTION:
GIVEN:
∠C = 90°
(A+B) + C = 180°
[sum of the interior angles of a triangle is 180° ]
(A+B) = 180° - ∠C
(A+B) = 180° - 90°
(A+B) = 90°
So, cos(A+B) = cos(90°)
cos(A+B) = 0
[Cos 90°= 0]
Hence, the value of cos(A +B) = 0
HOPE THIS WILL HELP YOU….

Answer 2

ABC is right angled triangle at C as shown in figure .

We know, sum of all angles of any triangle is equal to 180°
so, A + B + C = 180°
Here, C = 90°
A + B + 90° = 180°
A + B = 180° - 90° = 90°
A + B = 90°
Take cot both sides,
cot(A + B) = cot90° = 0
Hence, cot(A + B) = 0