ultrus Posted August 20, 2008 Share Posted August 20, 2008 Here it is: http://www.ultran.info/gamePlan1.gif How do I solve for x2 and y2? I remember seeing this in high school, but I can't recall it. Thanks much for any sanity you can provide. Link to comment https://forums.phpfreaks.com/topic/120461-simple-trig-problem-making-me-go-nuts/ Share on other sites More sharing options...
.josh Posted August 20, 2008 Share Posted August 20, 2008 x2 = 12 y2 = 16 I'm not a math whiz so I don't know how to officially figure it out, but here's what I did: c2 = 50 / 20 = 2.5 x2 = 40 / 2.5 = 16 y2 = 30 / 2.5 = 12 And to check: x2^2 + y2^2 = c2^2 16^2 + 12^2 = 20^2 256 + 144 = 400 In essence, I just like, scaled it, lol. Link to comment https://forums.phpfreaks.com/topic/120461-simple-trig-problem-making-me-go-nuts/#findComment-620741 Share on other sites More sharing options...
akitchin Posted August 20, 2008 Share Posted August 20, 2008 CV's right, because congruent triangles have the same trig ratios. therefore: x2 = (x1/c1) * c2 y2 = (y1/c1) * c2 where x1/c1 is the cosine and y1/c1 is the sine (assuming you consider the angle from the x-axis). just figured i'd offer a mathematical reason for it . Link to comment https://forums.phpfreaks.com/topic/120461-simple-trig-problem-making-me-go-nuts/#findComment-620765 Share on other sites More sharing options...
.josh Posted August 20, 2008 Share Posted August 20, 2008 And that's what makes me so great. I don't need no stinking math. Link to comment https://forums.phpfreaks.com/topic/120461-simple-trig-problem-making-me-go-nuts/#findComment-620778 Share on other sites More sharing options...
ultrus Posted August 20, 2008 Author Share Posted August 20, 2008 Heh thanks much! I was using the math to move xyz coordinates of stars in our sky to coordinates around a sphere. It worked! You can see the working result at www.christopherstevens.cc/fun . Click and drag your mouse to look up, down, left, right. Hold apple/ctrl+drag to zoom in and out. Hold option/alt+drag to move around horizontally. Now I just need to make it look pretty, and see if my stars are inverted and/or backwards. Link to comment https://forums.phpfreaks.com/topic/120461-simple-trig-problem-making-me-go-nuts/#findComment-621076 Share on other sites More sharing options...
Maq Posted August 26, 2008 Share Posted August 26, 2008 Heh, that looks pretty cool, gj! Link to comment https://forums.phpfreaks.com/topic/120461-simple-trig-problem-making-me-go-nuts/#findComment-626123 Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.