This is u this is u, this u now, this is u, u, u, u and u so this - if we distribute the cosine of u, this becomes cosine of u - let me put the y out front. so it's y cosine of u plus z cosine of u is equal to xyz sine of u. that's this first equation this second equation this second equation it looks like - well if we multiply both sides of this equation by yz we're gonna have xyz sine of u on the right hand side which is the exact same thing we have here. so let's multiply both sides of this equation by xyz, both sides. the right hand of the equation - no, not by xyz, just by yz
นี่คือ u นี่คือ u, u นี่ตอนนี้, นี่คือ u,u,u,u และ u แล้วนี่ - หากเรากระจายโคไซน์ของ u,