a2zinterviews

1.	Trigonometry:
	In a right angled Δ OAB, where BOA = θ,
	i .   sin θ = Perpendicular / Hypotenuse = AB/OB ii .  cos θ = Base / Hypotenuse = OA/OB iii .  tan θ = Perpendicular / Base = AB/OA iv .  cosec θ = 1/sin θ = OB/AB v .  sec θ = 1/cos θ = OB/OA vi .  cot θ = 1/tan θ = OA/AB

1.	Trigonometrical Identities:
	i .   sin2 θ + cos2θ = 1 ii .   1 + tan2 θ = sec2 θ iii .   1 + cot2 θ = cosec2 θ