How many seconds are in a day? use the conversion equivalency 24 hours = 1 day, 60 minutes = 1 hour, 60 seconds = 1 minute

< coa = 150 ( given)

as ba and bc are tangents

so oc and oa is perpendicular to cb and ab respectively because in circle normal passes through centre

so in quadrilateral oabc

< coa + < oab + < ocb + < abc = 360

150 +90+90 + < abc = 360

330 + < abc = 360

< abc = 360 -330 = 30

so < abc = 30

⭐dhruv⭐

the first one is x^2+2x+2

the second one is x^2+4

the last one is x^2-4x+8