Question

Разложите на множители:
1) ctg^2B-3
2) 1-tgB+1/cosB
3) 1-4cos^2B

Answer 1

1) ctg²β - 3 = $(ctg \beta + \sqrt{3} )(ctg \beta - \sqrt{3} )$

$3)1-4cos ^{2} \beta =(1-2cos \beta )(1+2cos \beta )$