cos(540°-θ)- sin(630°-θ)=?

প্রশ্ন: cos(540°-θ)- sin(630°-θ)=?

সমাধান:

আমরা জানি, cos(A - B) = cosA cosB + sinA sinB এবং sin(A - B) = sinA cosB - cosA sinB

cos(540°-θ) = cos(540°)cos(θ) + sin(540°)sin(θ)

এখন, 540° = 360° + 180°

সুতরাং, cos(540°) = cos(180°) = -1 😥

এবং, sin(540°) = sin(180°) = 0 👌

অতএব, cos(540°-θ) = (-1)cos(θ) + (0)sin(θ) = -cos(θ) 😊

আবার, sin(630°-θ) = sin(630°)cos(θ) - cos(630°)sin(θ)

এখন, 630° = 360° + 270°

সুতরাং, sin(630°) = sin(270°) = -1 😒

এবং, cos(630°) = cos(270°) = 0 🥰

অতএব, sin(630°-θ) = (-1)cos(θ) - (0)sin(θ) = -cos(θ) ✨

সুতরাং, cos(540°-θ)- sin(630°-θ) = -cos(θ) - (-cos(θ)) = -cos(θ) + cos(θ) = 0 🤩

অতএব, উত্তর: 0