 Let's draw ray diagrams to represent images for concave and convex mirrors. Let's start with the concave mirror. In the first case we have object beyond C. Where will the image be? Well, for this we can draw four rays of light. The first ray you can draw parallel to the principal axis. This ray after reflection will go through the focus. Why? Because all rays which are parallel to the principal axis after reflection goes to the focus. That's the meaning of the word focus. They get focused at this point. So that's ray number one. The second ray I can draw, I can draw through the focus and then this ray will become parallel to the principal axis. It's exactly opposite to the first one. The third ray I can draw through the center of curvature. This ray will just reflect back in the same direction. Why? Because the incident rays along the normal. Remember normal always passes through the center of curvature. So if the incident rays along the normal, reflected ray will always be along the normal as well. This is the law of reflection. Angle of incidence is zero. Angle of reflection is also zero. And the fourth ray we can draw at the pole and you make sure that the reflected ray has the same angle as this. And so these are now the four rays that you can draw and wherever they meet will be your image. So our image is over here. It is smaller than the object. It is inverted, which means it is real and you can see its position is between C and F. You don't have to draw all the four rays. You can draw any two rays you want because that's all you need and you can use that to draw your image. All right, let's go to this case where you have object between C and F. Where will the image be? The first ray I'll draw is parallel to the principal axis. This will go through the focus. The second ray I'll draw through the focus and this will go parallel to the principal axis. And that's all I need and I'll stick to only these two images. And as a result, notice now I'll get a large inverted real image beyond C. Okay, let's go to this case. Again, the first ray I'm going to draw parallel to the principal axis. This passes through the focus. The second ray I'll draw through the focus. It goes parallel to the principal axis and you can see the two rays meet right beneath the center of curvature. This means our image is at C and the object is at C. Same size and it is inverted, which means it's always real. Okay, let's go to this case. Then we'll come to this case. What if my object is between F and P? Again, the first ray I'll draw parallel to the principal axis, goes through the focus. Now the second ray, can I draw through the focus? No, it will not hit the mirror. So I can't do that. I will not draw through the center of curvature as well. This time I'll draw the ray through the pole. If it goes through the pole, I have to make sure this angle is the same as this angle and notice this time the two rays are not going to meet at all. They are diverging away from each other. Ooh, what does that mean? Well, if I were to extend it behind the mirror, now it appears that the two rays are coming from here. And therefore, if you were to look at it from here, it will appear as if there is an image. So this time we get a virtual image. How do I know that? It's erect. Erect images are always virtual images. It is behind the mirror and you can see it is bigger size than the object. Finally, we'll come to this case where the object is at F. Again, the first ray I'll draw parallel to the principal axis goes through the focus. And the second rail draw at the pole, make sure the reflected ray is having the same angle. And this time what I'll find is that the two rays are parallel to each other. They are neither going to meet here and even if I extend them behind, they will not meet, which means this time I will get no image at all. So when the object is at F, you get no image. So this way, just by drawing two rays of light, you can always identify where the image is going to be. You don't have to memorize the positions. All right. Now let's do convex mirror. This time you only have one case because the F and CR inside the mirror. So when you keep the object over here, there's only one case. The object is in front of the mirror. So just like before, I'm going to draw one ray of light that is parallel to the principal axis. This time this ray will not go through the focus because rays of light don't go inside the mirror. It will reflect such a way that it appears to come from the focus. So that's how we draw this ray. We need to be slightly more careful while drawing this way. The second ray I will draw through the pole, just like before, keeping these two angles exactly the same. And now you can see the two reflected rays, they are diverging just like before. So if I extend the rays behind, the two rays appear to be coming from here and from that I know that my image is going to be here. So you can see you get an erect virtual image inside the mirror between P and F and it is smaller than the object. Finally, what if the object is at infinity? Then we can draw parallel rays of light because when objects are at infinity, all rays of light are parallel. So we just draw two parallel rays of light and now we know that these rays of light should either go through the focus for concave mirror and for a convex mirror, they appear to reflect from the focus. And so you can see that means the image will be formed at the focus. This image will be point-sized. For concave, it will be a real image because it is converging and it is you can obtain it on a screen here and for a convex, it will be a virtual image because it is inside the mirror. It is diverging. And so just by drawing ray diagrams, you can figure out the position, the nature and the size of the image. You don't have to memorize those things.