学年

質問の種類

英語 高校生

40行目のForは接続詞として働いているのでしょうか? それと、問2の答えの②が謝りな理由が分からないので教えて頂きたいです。よろしくお願いいたします。

-第 13 講 however, is no. experience "Red" is not a color contained in an object. It is an 30 involving reflected light, a human eye, and a human brain. We experience red only when light of a certain wavelength (say, 600 nanometers) reflects from an object (in ② the midst of other reflections at other wavelengths), and only while a receiver translates this contrasting range of light into visual sensations. Our receiver is the 対をなす 15248 human *retina, (which uses its three types of photoreceptors, called *cones, to convert 35 the reflected light into electrical signals made meaningful by a brain. In a retina that's missing a medium or long cone, light at 600 nanometers is experienced as gray. And in the absence of a brain, there is no experience of color at all, only reflected light in the world. 脳の欠 (2) Even with the right equipment in place, the experience of a red apple is not a ST 40 done deal. For the brain to convert a visual sensation into the experience of red, it must possess the concept "Red." This concept can come from prior experience with apples, roses, and other objects you perceive as red, or from learning about red from other people. (Even people who are blind since birth have a concept of "Red" that they learn from conversations and books.) (Without this concept, the apple would be 45 experienced differently. For instance, to the Berinmo people of Papua New Guinea, apples reflecting light at 600 nanometers are experienced as brownish, because Berinmo concepts for color divide up the continuous *spectrum differently. These riddles about apples and trees invite us, as perceivers to

解決済み 回答数: 1
数学 高校生

(2)について質問です! (1)ででてきたxとyの関係式を変形するとPの軌跡になるのはなぜですか?🙇🏻‍♀️

疑問 11 極方程式 (III) ry平面上に2点A(a, 0),B(-a, 0) (a>0) が与えられているとき, 次の問いに答えよ. (1) P(x,y)が PA・PB=α をみたすとき,,yの関係式を求めよ. (2) 原点を極軸の正の部分を始線とする極座標を考えるとき,(1)に おける点Pが描く曲線の極方程式を求めよ. (3)(1) で求めたPの軌跡は'y's2a2 が表す領域に含まれることを 示せ. 精講 (2)7 ポイントIを利用すれば, 直交座標 (x, y) で表された図形 は,極座標 (r, e) を用いて表せます。 (3)ya に含まれる」 とは何を示せばよいのでしょう か? 7ポイントⅡによれば, r2=x2+y^ ですから,「re≦2a² を示す」こと になりそうです。 解答 (1) PA=√(x-a)2+y^, PB=√(x+α)'+y^ だから,19 PA・PB= α より {(x-a)2+y^}{(x+a)2+y^}=a^ {(x2+y^)+(a2-2ax)}{(x2+y^)+(a2+2ax)}=a^ (x²+ y²)²+2a²(x² + y²)+a²-4a²x²=a .. (x²+y²)²−2a²(x²-y²)=0......(*) 注うかつに展開してはいけません. ' + y' を keep しながら変形し ていくところがコツで,極方程式に変形するつもりなら絶対です。 (2) x=rcoso, y = rsin0 とおくと . x+y=r2, x-y'=r"(cos'0-sin'0)=rcos20 4-2a²recos20=0 ゆえに, 72=0 =0 または :.2(2-2a²cos20)=0 (*)に代入 r2=2a2cos20 ここで, r2=0 は, r2=2acos20 に含まれるので r2=2a2cos20

解決済み 回答数: 1