Question

The value of cotπ/20 cot3π/20 cot5π/20 cot7π/20 cot9π/20 is
A) -1
b) 1/2
c) 0
d) 1

Answer 1

cotπ/20 * cot9π/20 = 1

Answer 2

cot3π/20 *cot7π/20 = 1

Answer 3

So....u Need to find only cot5π/20

Answer 4

cot5π/20 = cot45 = 1

Answer 5

so 1*1*1 = 1

Answer 6

@Yahoo! thank you