Question

if cosA+sinA = 1 then prove that cosA-sinA =+-1​

Answer 1

Answer:

your questionbis wrong

Answer 2

Step by Step Explanation:

By Given,cosA+sinA=1

squaring both sides

cos2A+sin2A+2cosAsinA=1

⟹1+2cosAsinA=1⟹2cosAsinA=0

⟹−2cosAsinA=0⟹1−2cosAsinA=1

⟹cos2A+sin2A−2cosAsinA=1

⟹(cosA−sinA)^2=1

⟹cosA−sinA=±1