Question

if sin +cos =p then show that psquare -1/2=sin.cos ​

Answer 1

Answer:

Step-by-step explanation:

(p²-1)/2=sinФ. cosФ

{(sinФ+cosФ)²-1}/2=sinФ.cosФ

{sin²Ф+cos²Ф+2 sinФ cosФ-1}/2=sinФ . cosФ

{1+2sinФ cosФ -1}/2=sinФ . cosФ

(2sinФ cosФ)/2=sinФ . cosФ

sinФ.cosФ=sinФ.cosФ

Hence proved