How do you simplify (1+cos y)/(1+sec y)1+cosy1+secy?

2 Answers
Aug 5, 2015

(1+cosy)/(1+secy)=cosy1+cosy1+secy=cosy

Explanation:

secy=1/cosysecy=1cosy, therefore we have:

(1+cosy)/(1+secy)=(cosy/cosy)((1+cosy)/(1+1/cosy))=1+cosy1+secy=(cosycosy)(1+cosy1+1cosy)=
cosy((1+cosy)/(1+cosy))=cosycosy(1+cosy1+cosy)=cosy

Aug 6, 2015

Since secy = 1/cosysecy=1cosy, you can rewrite this as:

(1+cosy)/(1+(1/cosy))1+cosy1+(1cosy)

Thus, multiply through by ((cosy)/(cosy))(cosycosy):

= (cosy+cos^2y)/(cosy+1)=cosy+cos2ycosy+1

= cosy(cancel((1+cosy)/(cosy+1)))

= color(blue)(cosy)