Question

prove that cos 20 ( 1 + tan 20) = 1​

Answer 1

Step-by-step explanation:

cos20(1 + tan20)=1. (cos20) (sec20) = 1 cos 20

Answer 2

Answer:

prove that

cos 20 ( 1 + tan 20) = 1

consider LHS

=cos(20)(1+sin(20)/cos(20))

=cos(20)((cos(20)+sin(20))/cos(20)

=cos(20)+sin(20)

=1

LHS=RHS

Hence the proof.