Question

please answer this 2 maths question only if you know!!​

Answer 1

Answer:

13. -1

Step-by-step explanation:

cot A + 1/cot A =1

now, (cot A + 1/ cot A)( cot A + 1/ cot A) = 1

cot^2 A + 1 + 1 + 1/ cot ^2 = 1

cot^2 A + 1/ cot^2 + 2 = 1

cot^2 A + 1/ cot^2 = 1-2

cot^2 A +1/ cot^2 = -1

Hope it is useful!