Question

1+3cosA-4cos^2A÷1-cosA = (1+2cosA)^2

Answer 1

Answer:

LHS=RHS (PROVED)

Step-by-step explanation:

RHS:

(1+2cosA)²

=(1+2cosA)×(1+2cosA)

=1+2cosA+2cosA+4cos²A

=1+4cosA+4cos²A

=1+4cosA+4cos²A/1

Now, we multipling both numerator and denominator by (1-cosA),we get

=(1+4cosA+4cos²A) (1-cosA)/1-cosA

=1+4cosA+4cos²A-cosA-4cos²A-4cos³A/1-cosA

=1+3cosA-4cos³A/1-cosA (LHA)

SO,(LHS=RHS)[ Proved]

good night

I hope you anderstand my answer