Q. 3 G4.1( 14 Votes )
Prove the following identities.

Answer :
Consider LHS,
LHS =
Multiplying and dividing by sinθ + cosθ + 1,
⇒ =
×
We know that (a + b) (a – b) = a2 – b2.
⇒ =
=
We know that 1 – cos2θ = sin2θ and sin2θ + cos2θ = 1.
=
=
=
=
We know that = secθ and
= tanθ.
⇒ = secθ + tanθ
Multiplying and dividing by secθ – tanθ,
⇒ = secθ + tanθ ×
=
We know that sec2 – tan2θ = 1.
∴ =
= RHS
Hence proved.
Rate this question :






















Prove the following identities
sec2θ + cosec2θ = sec2θ cosec2θ
Tamil Nadu Board - MathIf sinθ, cosθ and tanθ are in G.P., then prove that cot6θ – cot2θ = 1.
Tamil Nadu Board - MathProve the following identities.
Prove the following identities.
If x = a secθ + b tanθ and y = a tanθ + b secθ, then prove that x2 – y2 = a2 – b2.
Tamil Nadu Board - MathProve the following identities.
Prove the following identities.
Prove the following identities.
Prove the following identities.
Prove the following identities.