Question

if cot A +1/cotA=2, prove that cot²A+1/cot²A=2​

Answer 1

cotA+1/cotA=2

squaring on both side

(cotA+1/cotA)²=4

cot²A+1/cot²A+2cotA.1/cotA=4

cot²A+1/cot²A +2 =4

cot²A+1/cot²A=4-2

cot²A+1/cot²A= 2 ..Hence Proved