Question

a)1-sin^2A/cos^2A b)1-cos^2A/1-sinA c)(1+tg^2A)*cos^2A-sin^2A d)(ctg^2A+1)*sin^2A-cos^2A

Answer 1

а)1-sin^2A/cos^2A=sin^2A+cos^2A-sin^2A/cos^2A=cos^2A/cos^2A=1

b)1-cos^2A/1-sinA= sin^2A+cos^2A-os^2A sin^2A+cos^2-sin^2A=sin^2A/cos^2A=tg^2A

c)(1+tg^2A)*cos^2A-sin^2A= cos^2 a + sin^2 a - sin^2 a = cos^2 a

d)????